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Legal case

Do unions have to specify dates of planned strikes?

A trade union is given various protections in UK law as long as there is a genuine trade dispute and the industrial action is organised.

A trade union is given various protections in UK law as long as there is a genuine trade dispute and the industrial action is organised according to the strict balloting and notification rules set out in the Trade Union and Labour Relations (Consolidation) Act 1992. If rules are not adhered to, an employer can apply for an injunction to stop a strike going ahead.

In Thomas Cook Airlines Ltd v British Airline Pilots Association the High Court considered whether a trade union is required to identify on the voting paper the specific dates on which a period of discontinuous industrial action would be taken in order to comply with the Act’s provisions.

What happened?

Thomas Cook sought an injunction to restrain the trade union from calling a strike over the pay and conditions of the pilots it employed.

Following a ballot, union members had voted in favour of taking industrial action. The union asserted that the ballot complied with the requirements of the Act and therefore their call for industrial action was lawful. The airline, however, argued that the proposed industrial action was not afforded such protection because the ballot failed to comply with the requirement about the dates of action.

The relevant part of the ballot stated as follows:

“It is proposed to take discontinuous industrial action in the form of strike action on dates to be announced over the period from 8th September 2017 to 18th February 2018”

Thomas Cook’s representatives argued that the union’s expectation as to when strike action would occur was more specific than the five month time frame stated in the ballot.

The law

The relevant section requires the union to ensure that: The voting paper must indicate the period or periods within which the industrial action or, as the case may be, each type of industrial action is expected to take place.”

This is a new provision introduced to the Act. It took effect on 1 March 2017. This was the first time it has been considered by a court.

In considering the injunction application, the court had to consider the likelihood of the union succeeding at a trial to argue that the ballot fell within the scope of protection.

It was accepted, therefore, that the question to be asked was whether it was more likely than not that the union failed to comply with the relevant section of the Act.


The judge rejected the application, finding that it was more likely than not that the union had complied with the requirement in the Act.

The subsection does not specify what level of detail about the information is required. It was considered unlikely that a court would require more detail to be provided than was included in the union’s ballot in this case. Consideration was given to the fact that requiring more detail was likely to make the requirement vague and unworkable. It would be difficult to specify exactly what additional detail was required, and this could make it more difficult for trade unions to comply.

The court also acknowledged the uncertainties which are inherent in a trade dispute. It therefore recognised that it typically was not possible to precisely identify dates on which action was to take place as they would depend on both factors that were not known before the ballot papers are sent out, and variables that are entirely outside the union’s control. The union was not required to provide its best guess as to how and when the dispute would end.

The fundamental purpose of the subsection, as set out in the Explanatory Notes which accompany the Act, is to ensure that trade union members know what they are voting for, thereby enabling them to make an informed decision as to how to vote. Therefore, for this purpose, the notice was considered to be sufficiently clear.

The court, therefore, held that, even if the union did have some clearer idea when they expected strike action to take place, the provision did not impose any obligation to include this in the ballot.

What this means for me?

When faced with the prospect of discontinuous industrial action over a long period of time it is unlikely that you will have any recourse to challenge the strike under this provision in the Act. You cannot require the union to specify exact dates of proposed industrial action in its ballot, and, therefore, cannot challenge the legality of the industrial action on this basis. This is contrary to what many commentators believed the Government was seeking to achieve by introducing this provision. Inevitably, the greater the uncertainty around the dates of proposed strike action, the more difficult it will be to plan around any disruption.

Paul McFarlane, Partner, ( and Rebecca Hyde ( are members of our Employment, Pensions and Immigration Team based in London.

If you require expert advice on the legality of a proposed strike or any other aspect of the law on industrial action, please do not hesitate to contact Paul or Rebecca or please speak to your usual Weightmans advisor.

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