Striking Times (2): managing industrial action

United Kingdom

As we discussed in our previous Law-Now Striking times: preparing for industrial action a wide variety of employers are facing the potential for industrial action this Summer. Since our last report, more rail strikes are expected to coincide with the Commonwealth Games, BT engineers and call centre staff are gearing up to set dates for strike action having voted overwhelmingly in favour and Barristers began their 4-week strike on 27 June, with more to follow in August. 

In this Law-Now we briefly look at the issues employers need to be mindful of when managing industrial action and signpost some of the legal risk areas.

Is it official and protected industrial action?

Industrial action is unofficial if it has not been authorised by the trade union. Known as “wildcat action”, it is generally a thing of the past, but those who do take part have very few legal protections. In particular, where employees participate in such action, the employer can usually demand full performance, withhold pay, lock out staff, use substitute labour and dismiss those taking part whilst remaining immune from unfair dismissal claims.  

Official industrial action (i.e. approved or endorsed by the trade union) must be lawfully organised by the union otherwise the union will lose its statutory immunity against liability for certain torts, including inducing a breach of contract. This may happen when the union has failed to comply with the balloting and notification requirements for industrial action, although in practice the union would likely withdraw its support for the action and advise its members accordingly. Employers will have immunity from unfair dismissal claims if they dismiss those taking part in official industrial action that isn’t protected, provided however that they are not selective in who they dismiss (or subsequently re-engage) and the individual had not ceased to take part in the action when notice of dismissal was given or, if none was given, on the termination date.

Where industrial action has been lawfully organised and endorsed by the union it will be protected


The law relating to dismissing employees who are participating in protected industrial action is a minefield and great care must be taken to avoid procedural errors that could result in unfair dismissal liabilities. The legislative rules mean that an employee cannot be fairly dismissed for taking part in protected industrial action for at least 12 weeks after they began to participate and possibly longer depending on the circumstances. 


Regardless of the status of industrial action, an employer may lawfully withhold pay from an employee for the period that they are taking part in a strike. Employers do not have to accept partial performance from an employee.

When are employees “taking part” in industrial action?

Generally speaking, employees who have begun to participate in industrial action are treated as continuing to do so until the action is called off, unless they return to normal working or inform the employer that they are no longer taking part (and do not do so). However, tricky issues arise in relation to employees who call in sick during industrial action and/or who are on holiday. 

Employers should anticipate the possibility that an employee may call in sick as a means of supporting the industrial action without taking part in it. Subject to the employer’s sick pay scheme rules, employers may wish to make clear in advance of any industrial action that it will require proof of any illness by medical certification from day one.    

Where strike action begins during a period when an employee has pre-planned annual leave, then in the absence of any evidence that they are actually taking part in industrial action, they should be treated as being on leave and not on strike. However, employees will be taking part in the strike if they associate themselves with the strike, for example by attending a picket line during their holiday.

Action short of dismissal

Although the law provides protection against dismissing an employee for taking part in official and protected industrial action, it has recently been confirmed that an employer may lawfully impose action short of dismissal for taking part in official industrial action.

In Mercer v Alternative Future Group Ltd the Court of Appeal confirmed that it was not unlawful for an employer to suspend an employee who, as the Unison workplace representative, had organised industrial action. Mrs Mercer argued that this suspension amounted to an unlawful detriment under s.146 of the Trade Union and Labour Relations Consolidation Act 1992 (TULRCA) which protects workers from detrimental treatment for taking part in trade union activities “at an appropriate time”.   She maintained that her organisation and participation in industrial action amounted to such trade union activities at an appropriate time. The Court of Appeal did not agree. Whilst it considered that s.146 was potentially incompatible with Article 11 of the European Convention on Human Rights, which guarantees freedom of assembly, the court did not consider that it was the court’s role to engage in judicial legislation to extend the protection, and that the policy issues arising were best left to Parliament.

This may not however be the end of this issue. It is it is understood that the case may be subject to further appeal to the Supreme Court. In the meantime, employers should tread carefully and take legal advice before subjecting any employee to a detriment because they are taking part in industrial action. 

Managing the disruption on staffing levels

As we outlined in our previous Law-Now, Regulation 7 of The Conduct of Employment Agencies and Employment Businesses Regulations 2003 currently prohibits employment businesses from introducing or supplying work-seekers to hirers to cover the duties of workers taking part in industrial action or to replace individuals who have themselves been transferred by the hirer to carry out the duties of employees taking part in industrial action.

We also explained that the government had announced its intention to repeal this ban. The draft Regulations intended to do just that have now been published and were laid before Parliament on 27 June 2022, in the form of the Draft Conduct of Employment Agencies and Employment Businesses (Amendment) Regulations 2022. MPs voted 289-202 to approve the Regulations on Monday 11 July 2022. A House of Lords vote is awaited.

If this legislation is brought into force, the use of agency staff will be an option for employers. This will have the greatest impact on sectors where there is a supply of agency staff with the skills available to carry out the roles of striking workers.


Managing industrial action will often involve trying to manage picketing and disruption caused by picket lines outside the workplace. The government published a Code of Practice on Picketing in 2017.

Where picketing has been organised or encouraged by a trade union, certain requirements must be met: the union must appoint a picket supervisor; and the police should be informed of the supervisor’s name and contact details and when the picket will take place. The picket supervisor should carry a letter of approval from the union which the employer may request sight of.

Picketing must be “peaceful picketing”. It should not involve any intimidation or threatening behaviour. Its purpose must be to obtain or communicate information or to persuade others on whether or not to work. It must only be undertaken by a worker of the employer or trade union official. Whilst picketing is intended to take place outside the workplace, a form of picketing often now occurs via social media, which can be more difficult to manage and control. 

When the government was originally proposing to introduce changes to the law on picketing in 2016/2017, it intended to require unions to publish picket and protest plans and state in advance if they expected to use social media during their campaign and what they planned to publicise on their websites. 

However, these proposals were never implemented and there is currently no specific prohibition or guidance on the use of the press and social media to publicise industrial action/picketing. Employers should monitor such publicity and raise with the union any attempts to incite anything other than lawful and peaceful picketing by this means. 

Communication and conciliation

Throughout industrial action, ongoing communication with employees is important. Using online communications/social media may help convey information to a wide audience quickly, but it may also help in gauging employees’ feelings as the industrial action progresses. 

Keeping dialogue open with the unions is also important, if for no other reason than to demonstrate to the workforce that the employer is being reasonable and is open to a resolution.