Industrial action: things to consider

With a host of strikes threatened this summer, Eric Gilligan and Tracey Marsden highlight the key considerations for employers

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Is it an 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 withhold pay, lock out staff, use substitute labour and dismiss those taking part while remaining immune from unfair dismissal claims.  

Official industrial action (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. Employers will have immunity from unfair dismissal claims if they dismiss those taking part in official industrial action that isn’t protected, provided that they are not selective in whom 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.


The law relating to dismissing employees who are participating in protected industrial action is a minefield and great care must be taken to avoid 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. 

Action short of dismissal

Although the law provides protection against dismissing an employee for taking part in official and protected industrial action, it was recently confirmed in Mercer v Alternative Future Group Ltd that an employer may lawfully impose action short of dismissal for taking part in official industrial action; however, it is understood that the decision may be subject to further appeal and employers should accordingly tread carefully.

Managing the disruption on staffing levels

The Conduct of Employment Agencies and Employment Businesses Regulations 2003 currently prohibits employment businesses from introducing or supplying work-seekers to cover the duties of workers taking part in industrial action. However, the government had announced its intention to repeal this ban. The draft regulations intended to do just that  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 11 July and 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. 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, as well as when the picket will take place. 

Picketing must be ‘peaceful’. It should not involve any intimidation or threatening behaviour. Its purpose must be to obtain or communicate information or to persuade others whether or not to work. It must only be undertaken by a worker of the employer or trade union official. 

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 l picketing by this means. 

Communication and conciliation

Throughout industrial action, ongoing communication with employees is important. Using online communications or 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. 

Eric Gilligan and Tracey Marsden are partners at CMS