Industrial action raises complicated issues and legal advice should always be taken.

The core legislation is the Trade Union and Labour Relations (Consolidation) Act 1992 (`TULCRA`) which has been amended over time, the most recent additions arising out of the Employment Relations Act 2004 and the Trade Union Act 2016.

Trade Union Act 2016

The majority of provisions of the Trade Union Act 2016 came into force on 1 March 2017. These included provisions concerning the majorities required in balloting, the increased powers of the Certification Officer, and the procedures for picketing.

Other provisions in the Act were phased in over a transitional period. A provision came into force in 2018 specifying that new union members do not contribute automatically to a union’s political fund – they must opt-in. Also in force from this time are new rules concerning ‘check-off’ (deducting trade union membership subscriptions from salary). Trade unions must now pay the administrative costs for collecting union subscriptions using check-off in the public sector, and in some private sector employers providing public services. 

Future developments arising from the Act may include:

  • A move towards electronic balloting. A review was held in 2017 and the outcome was in favour of introducing electronic balloting, but the government has yet to decide whether to implement this part of the Act.
  • Future restrictions on facility time (paid time off given to trade union representatives to perform their union duties). Regulations introduced in 2017 require public sector employers to report on the amount of facility time taken and the cost involved, and the Act enables possible future regulations restricting facility time for particular sectors. The time spent by union reps on union activities during their working hours may be capped in the future.

Useful information on dealing with trade unions and industrial action is available from a number of sources. The government has produced guidance If your business faces industrial action and published a Code of Practice: access and unfair practices during recognition and derecognition ballots. The TUC has produced a Guide to industrial action.

These Q&As deal with recognising trade unions for bargaining purposes and responding lawfully to industrial action. They should be read alongside our Case law on trade union recognition and industrial action

For information on collective consultation for redundancy purposes, see our Redundancy collective consultation Q&As.

As a general rule, collective bargaining involves negotiations on pay, hours and holidays (the core terms). Parties often voluntarily reach agreement on other issues.

There must be clear evidence to show both parties have mutually recognised one another for the purposes of collective bargaining, and evidence of actual negotiations on collective agreements. Discussions with a union about various matters over a long period of time doesn’t make those talks legally recognised. In the UK, employees and employers make their own individual employment contracts with each other and collective employment rights are not legally enforceable unless a collective agreement is specifically incorporated into an employee’s contract. This is in contrast to the law in many EU member states. 

The question as to whether a collective agreement has been incorporated into an individual’s contract can be difficult to resolve. For the agreement to be incorporated into contracts there should be:

  • express provision in the contract to that effect
  • a statement that the employee in question intends to be bound by the agreement and by any changes to that agreement which happen after the date the contract was formed
  • evidence of custom and practice that this term is incorporated into the contract.

It is understandably the third issue which can cause confusion and so it is advisable to decide at the outset as to whether the collective agreement is to be incorporated and for the employee to be bound by future changes, if that is what is desired. This is known as a `bridging term` (see Lee v GEC Plessey Telecommunications, 1993).

The Central Arbitration Committee (CAC) is an independent tribunal with statutory powers. It provides voluntary arbitration in industrial disputes and has statutory responsibility to adjudicate disputes regarding recognition, and applications for the disclosure of information for collective bargaining purposes. It also deals with applications and complaints under the Information and Consultation Regulations 2004 and disputes over the establishment and operation of European Works Councils.

The Certification Officer works with the Department for Business, Energy and Industrial Strategy and is responsible for statutory functions relating to trade unions and employers’ associations. The Certification Officer’s powers were extended in the Trade Union Act 2016. The office now has greater powers in relation to the investigation of union actions and can operate a 'quasi judicial' function and make decisions which could thereafter be appealed via the court system.

The legal right to conduct collective bargaining is the essential basic feature of a recognised trade union.

There have been many academic articles written about the complexities of UK union recognition. In practice, the line between recognition and non-recognition can often blur.

A trade union is recognised when it is:

  • independent, and
  • recognised by an employer, or two or more associated employers, for the purpose of collective bargaining. Collective bargaining has a very specific definition (see Collective bargaining).

Trade union recognition can either be by voluntary agreement between the parties, or a trade union can apply for statutory recognition (a procedure introduced in June 2000 under the Employment Relations Act 1999).

The procedure involves an independent trade union (or two or more trade unions acting together) making a request for recognition.

If the employer, together with any associated employer, employs fewer than 21 workers on the day that the request is received, the request is invalid as far as the legislation is concerned. It is, therefore, voluntary for employers with fewer than 21 workers to recognise a union.

Note that the definition of a ‘worker’ is set out in various pieces of legislation and is a complex area in employment law. Workers who supply services to an organisation as the end user may qualify for union membership, but this will usually be in relation to the agency that supplied them which would mean they would not count towards the threshold of 21 for the end-user organisation.

Following the declaration of statutory trade union recognition, the parties have 30 working days to agree the way they’ll conduct collective bargaining. If they fail to reach agreement either party may apply to the CAC for assistance.

If the parties cannot agree, the CAC will impose a method of collective bargaining, which will take effect as a legally enforceable contract made between the union and the employer.

Trade unions that achieve statutory recognition are entitled to:

  • receive information from the employer for the purposes of collective bargaining
  • time off for trade union duties and/or activities for their trade union officials and learning representatives 
  • be consulted in respect of collective redundancies (s188 TULCRA) 
  • be informed and consulted in relation to proposed TUPE transfers
  • information and consultation in relation to health and safety matters and pension schemes.

TULCRA also provides protection from detriment or dismissal in relation to membership of a recognised trade union in various circumstances. As with employees, there are remedies in law for workers who have been offered an inducement not to join a union or who suffer a detriment because of their union membership, but this does not give a worker the right to claim unfair dismissal.

A trade union which has been recognised for collective bargaining may only be derecognised where:

  • the employer no longer employs 21 or more workers. If the employer’s application to have the union derecognised is accepted by the CAC, the collective bargaining arrangements will cease to have effect
  • the union no longer enjoys the necessary degree of support from workers in the bargaining unit. Here the employers/workers can apply to the CAC for a derecognition ballot. The process is the same as that for recognition.

An application for derecognition can’t be made until at least three years have elapsed since the declaration of recognition.

An employee dismissed on grounds relating to the recognition or derecognition of a union will be able to bring a claim for unfair dismissal, regardless of their length of service.

They have three months from the date on which they were subjected to a detriment to bring a claim. The employment tribunal may make a declaration that the employer acted unlawfully and award compensation.

The Acas code of practice on time off for trade union duties and activities focuses on protection for representatives of independent trade unions in connection with collective bargaining, including duties concerning collective redundancies and the transfer of undertakings.

Industrial action is used as a generic term, covering a broad range of actions by employees to put pressure on an employer. Some examples are strikes, overtime bans, boycotts and working to rule. A lockout is a term used to describe a situation in which an employer prevents employees from working.

In law, a strike has been defined as both:

  • any concerted stoppage of work’ (Trade Union and Labour Relations (Consolidation) Act 1992), and
  • the cessation of work by a body of employed persons acting in combination, or a concerted refusal, or a refusal under a common understanding, of any number of employed persons to continue to work for an employer in consequence of a dispute, done as a means of compelling their employer or any employed person or body of employed persons, or to aid other employees in compelling their employer or any employed person or body of employed persons, to accept or not to accept terms or conditions of or affecting employment (s235(5) Employment Rights Act 1996).

While there is no right to strike, there are circumstances in which a strike is lawful. For there to be an authorised or official strike, the union must organise a legal ballot. Employers must be:

  • given written notice no less than seven days in advance of the opening of the ballot or the union’s intention to ballot
  • sent a sample voting paper three days before the ballot opens
  • be given at least 14 days’ notice of intended industrial action but, prior to this, to have been informed of the ballot result.

A ballot will not be valid unless there is a minimum 50% turnout. In certain ‘important public services’ (such as the NHS, the fire service and public transport) there must be a threshold of 40% of votes in favour of strike action.

The proposed stoppage of work must be in ‘contemplation of’ or ‘furtherance of’ a trade dispute between the employer and the union members which, if the industrial action is lawfully convened, will give those taking part statutory immunity from breaking the law.  There is case law on what amounts to a trade dispute and whether it has given rise to a lawful strike (see below for more on trade disputes).

The law concerning balloting changed under the Trade Union Act 2016 and the government’s Code of Practice: Industrial action ballots and notice to employers was updated accordingly.

Note that not all types of unionised workforces are allowed to take strike action. The army, police and, to a limited extent, the prison service cannot strike.

As noted, there is no general right to strike as such in UK law, but the Human Rights Act 1998 gives a legal right to 'freedom of assembly and association'. This was confirmed by the European Court in the case of Wilson v UK (2002).

Time spent on strike is not included in calculating the length of an employee's period of continuous employment (s216(1) ERA 1996).

An employee who is dismissed while on an unofficial strike is usually unable to make an unfair dismissal claim, but employers should take legal advice in this situation.

The three-month time limit for presenting an unfair dismissal claim to a tribunal doubles to six months if the employee was on strike when they were dismissed. This is to allow for a `cooling off period` where further negotiations might take place or decisions might be reversed.

Any form of industrial action, including a strike, which is not authorised or endorsed by a trade union, will generally be ‘unofficial.’ This will include where a non-member of a union purports to join in with strike action.

Where industrial action is unofficial, participating employees do not have statutory protection from unfair dismissal.

Some professions are banned from taking industrial action and for them striking will always be illegal. For example, industrial action by prison officers is prohibited by the Criminal Justice and Public Order Act 1994.

A 'trade dispute' is one that relates wholly or mainly to:

  • Terms and conditions of employment, and the physical work environment
  • Allocation of work or the duties of employment between workers or groups of workers
  • Engagement or non-engagement, termination or suspension of employment, or the duties of employment between workers
  • Matters of discipline, membership or non-membership of a trade union
  • Facilities for trade union officials
  • Machinery for negotiations or consultation and other procedures relating to the above matters.

An employer may consider applying for an interim injunction from the High Court to prevent the industrial action from taking place or continuing. The court has to decide whether:

  • there is a serious issue to be tried and a reasonable claim for the relief sought (the balance of convenience), and
  • damages would provide an adequate remedy, given that the level of damages that may be awarded is limited.

This is a complex area of law and specific legal advice should always be sought. In order to obtain an injunction, the employer will assert that the strike needs to be stopped as it is somehow unlawful. Case law has considered this in some detail; examples are Royal Mail Group v Communication Workers Union (2019), where the issue was whether the ballot process was faulty and whether the employer could hinder the voting process (which it may not), and Thomas Cook Airlines v BALPA (2017), in which the employer was incorrect to allege that the ballot voting paper should have specified the date of the proposed industrial action.

An employer could consider suing its employees for damages as an alternative to dismissal (or, indeed, potentially in conjunction with dismissal). Where production stops, it may well be possible to quantify lost profits for the days on which the action is taken. The problem, however, is that employees will clearly have limited resources and the industrial relations consequences need to be considered carefully. Clearly, where an extended strike takes place, an employer will not pay the employees. This will be irrespective of whether they are dismissed or sued for damages.

Secondary action consists of calling or threatening a strike or other industrial action by workers of an employer who is not a party to a dispute. This is usually unlawful and unions that organise such action may lose immunity from consequent legal proceedings. 'Secondary action' is defined by the Trade Union and Labour Relations Consolidation Act 1992 as where someone:

  • induces another to break a contract of employment or interfere or induce another to interfere with its performance, or
  • threatens that a contract of employment under which they or another is employed will be broken or its performance interfered with, or that they will induce another to break a contract of employment or to interfere with its performance, and 
  • the employer under the contract of employment is not a party to the dispute.

The illegality of secondary action can be a complex issue. The only form of secondary action that is lawful is picketing, but there are strict rules concerning the numbers and use of pickets.

It is lawful for a person on strike to picket on a public highway near their place of work:

  • in contemplation of or furtherance of a trade dispute, or
  • for the purposes of peacefully obtaining or communicating information, or
  • to persuade anyone to abstain from working.

Usually, trying to get another person to break their contract or interfering with the performance of a contract is unlawful. An example might be attempting to persuade a delivery driver who works for someone else not to enter the workplace and thus breach their own employment contract. This would, on the face of it, be an illegal inducement for that driver to break their contract. It would nevertheless amount to lawful action for the picketers (as long as it is peaceful). Lawful picketing provides protection from liability in these circumstances.

It is not lawful to picket on any part of the premises that is private property – that would be trespass. If attendance outside the place of work is for any other purpose, such as obstructing the highway, then this is unlawful.

There is no statutory restriction on the number of pickets that may attend at a place of work, but the action must be peaceful to retain statutory protection. The Department for Business, Energy & Industrial Strategy’s Code of Practice: picketing recommends no more than six pickets at any entrance or exit from the workplace. The Trade Union Act 2016 introduced the requirement for there to be picket supervisors on duty where picketing takes place.

The police have separate powers under the Public Order Act 1986 to impose limits of 20 where an assembly is likely to result in serious public disorder. The current Police Crime Sentencing and Courts Bill 2021 is likely to increase those police powers.

In the case of partial performance of an employment contract, such as a work to rule, employees will not be paid remuneration unless they are able and willing to perform their contractual duties in full. This can cause difficulties when trying to decide if working to rule amounts to a refusal to fulfil contractual duties or not.

The courts, however, have taken the view that there is an implied term to serve the employer faithfully which extends to an obligation not to disrupt the employer's business wilfully or to operate to the letter of the contract in such a way as to undermine the commercial objectives of the contract. In general, since a work to rule will clearly be intended to disrupt the business, it is likely to amount to a breach of contract by the employee and, therefore, a refusal to comply with the employee's duties in full.


No. The Employment Relations Act 2004 introduced measures that:

  • established rights for workers (which will also include employees) not to be offered inducements relating to trade union membership and collective bargaining, and
  • extended their rights not to suffer detrimental action in circumstances relating to union membership.

Unions cannot generally refuse to admit members unless they belong to organisations whose membership would be contrary to the rules of the union. For example, a union may be able to refuse membership to members of an extremist political party.

If the action is unofficial the employer may be able to:

  • obtain an injunction (to stop the strike in its tracks) and/or
  • sue the union for damages, though the amount the trade union can be ordered to pay is capped by reference to the number of members it has nationwide.

However, the legislation concerning industrial action is full of complexities and employers may find many ways to challenge the legitimacy of strike action.

Unofficial industrial action

If an employee is taking part in unofficial industrial action at the time of their dismissal, they will not have the right to claim unfair dismissal.

To dismiss unofficial strikers without a dismissal procedure:

  • the industrial action must not be authorised or endorsed by the relevant union
  • the employee needs to be shown to have been participating in the action – rather than, for example, being absent from work due to illness – and to have been dismissed while participating, both of which are important matters of fact.

Any employee who participates in unofficial industrial action will also commit a breach of their contract of employment. The main remedies would be:

  • Suing the employee for damages (that is the loss suffered as a result of the industrial action. This is usually not a commercial option because it is hard to prove and the employees are unlikely to be able to pay the amount sought, even if an employer is in principle willing to sue).
  • Non-payment of the employees.
  • If the circumstances warrant it, dismissal.

However, great care should be taken (the action may turn out to be official or the employee may be able to show they were dismissed for one of the 'automatically unfair' reasons).

Official industrial action

Statutory protection is provided to employees taking part in official action. Employees are allowed to strike for a protected period of 12 weeks.

It is automatically unfair to dismiss an employee for taking part in protected industrial action where dismissal occurs:

  • within the first 12 weeks of the industrial action (the protected period), or
  • after the protected period, if the employee has stopped participating in the protected action before the end of the protected period, or
  • after the protected period, if the employee is still participating in industrial action but the employer has not taken procedural steps to resolve the dispute, for example, the compliance with any collective agreement for dispute resolution, any other attempt to negotiate or resolve the dispute with the use of mediation services.

However, the employees can be dismissed fairly if the official action continues beyond the 12-week protected period, and the employer has tried to take reasonable steps to resolve the dispute.

All those participating must be dismissed and remain so for a three-month period. The dismissed employees will not be entitled to receive any notice pay, redundancy pay or other termination payment. Problems can arise if there is a fresh ballot on essentially the same issues and the employer alleges that the 12-week period has been exceeded.

Ultimately, a court has to decide whether the dispute is sufficiently the same and whether the clock for the protected period starts running again.

Reasonable steps

An employer seeking to dismiss striking employees after the protected period must take such procedural steps as are reasonable to resolve the dispute. After the protected period of industrial action has begun, the employer must:

  • offer or agree to start or restart negotiations
  • not unreasonably refuse a request to make use of conciliation or mediation services.

Where the parties have agreed to use the services of a mediator or conciliator, section 28 of the Employment Relations Act 2004 introduces matters which the tribunal is to have particular regard to when assessing whether an employer or a trade union has taken reasonable procedural steps to resolve the dispute.

Government guidance clearly states that employers cannot hire agency staff to provide temporary work cover during a strike, but businesses can continue to use agency staff who are already in place in the business. These workers can carry on as usual.

The legality is dependent on the work the employer wants the temporary workers to do and whether the employer engages the workers directly (in which case these workers continuing to work is permissible). The employer can at any time use an employment agency to supply them with workers, including during a strike, but they must not be `agency workers` (in other words, employed by the agency itself) and would need to be employed by the organisation itself (the end-user). 

Agency workers thus supplied, or already employed, must not be specifically moved from one area of the business to the area affected by the strike to do work normally performed by the strikers.

The Trade Union Act 2016 envisaged a relaxation of these provisions which has not yet been brought forward.

The basic rule is that employees are not performing under the terms of their contracts while they’re on strike, so the time is treated as authorised unpaid leave.

Employers may close their premises for the day but, if they stay open as usual, they should clearly inform all employees of this in case there are employees who decide they do not wish to participate in the strike. If employers do close the workplace for one day, they should pay employees who are not striking, unless there is a clearly worded contractual lay-off clause.

Refusing to employ or ‘blacklisting’ union members gives rise to legal claims for defamation, conspiracy and breach of data protection laws.

Blacklisting will occur where an employer is found to be systematically compiling information on trade union members (called 'prohibited lists') with a view to discriminating against them on the basis of their union membership and activities. Both employees and workers are protected under the Employment Relations Act (Blacklisting) Regulations 2010 and government guidance.

It is unlawful for organisations to:

  • refuse employment to, or to blacklist, union members
  • refuse employment or dismiss individuals as a result of appearing on a blacklist
  • refuse to provide a service on the basis of an individual appearing on a blacklist.

Individuals or unions can pursue compensation or solicit action against those who compile, distribute or use blacklists.

Historically, blacklisting was a particular problem in the construction industry, prompting the creation of the Construction Workers Compensation Scheme which closed in June 2016.

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