Secretary of State for Business and Trade v Mercer [2024]

Secretary of State for Business and Trade v Mercer [2024]

The long and winding road of the Mercer case has taken yet another U-turn. The Supreme Court’s judgment, published on 17 April has brought some clarity and potentially some finality to a difficult area of UK trade union law (even if the practical implications are yet to be worked out). 

In short - the legislative protection granted to striking workers, which crucially fails to protect striking workers from being subjected to a detriment short of dismissal for going on strike during working hours, has now been declared as incompatible with Article 11 of the European Convention on Human Rights (the right to form and join trade unions). This declaration is one of the biggest developments in UK trade union law for decades, and is going to have significant ramifications for employers, trade unions and striking workers in the coming years. We expect this to become a hot political issue in the near future, particularly if there is a change in government later this year. 


To understand the importance of the Supreme Court’s decision, it is worth taking a brief trip back down the winding road to see where we started, and how we have got to this point. 

The legislation

The starting point is the legislation. Section 146 of the Trade Union and Labour Relations (Consolidation) Act 1992 (“TULRCA”) protects workers from suffering detriment as a result of having taken part in trade union activities at an appropriate time (which, generally, means outside of working hours). Section 152, a sibling provision, extends this to protection against dismissal, again in the context of a worker who has taken part in trade union activities at an appropriate time. Section 237, which is part of a different set of provisions in TULRCA, affords a limited protection against dismissal for those who participate in lawful industrial action. Given the different set of contrasting provisions, and the fact that industrial action will generally always take place during working hours for it to have the desired disruptive effect, the conventional interpretation has been that the Section 146 protection against detriment does not expressly apply to those who go on strike during working hours. This gap in the law has enabled employers to lawfully take disciplinary action (short of dismissal) against workers who go on strike during working hours. 

The Employment Appeal Tribunal

When this case went to the Employment Appeal Tribunal in 2021, the legal position on this point was brought into question. The EAT decided that the Section 146 protection needed to be interpreted so as to give striking workers protection against detriment, in order for it to be compatible with Article 11 (an insight of what was to come), and that it was possible to do so by reading additional words into the legislation. The Government, as intervenor, succeeded in being granted leave to appeal the EAT’s decision to the Court of Appeal. 

The Court of Appeal

The Court of Appeal overturned the EAT’s decision, despite acknowledging that there was a gap in protection for striking workers. This was based on two main grounds:

  1. it was not clear from European case law that employers should be absolutely prohibited from taking formal action (short of dismissal) against striking workers, so the gap was not necessarily a breach of Article 11 (although it could be); and
  2. in any event, it was not possible to read Section 146 in a way which addressed this gap in protection in order to be fully compatible with Article 11 – this would require a re-writing of TULRCA by the courts and would instead have to be addressed by Parliament. See our article on this decision here.

The Supreme Court judgment

So now post-Supreme Court, we finally have some clarity on the big questions of law raised in the context of this case. The central findings made by the Supreme Court were as follows:

  • The right to strike is protected by Article 11, but it is not a core right, nor is it absolute. This means that while the UK does have a proactive obligation to protect the right to strike, as the regulator of relationships between employers and workers, it is not required to provide universal protection in all circumstances to all workers against any detriment intended to dissuade them from participating in a lawful strike. The legislation therefore has to strike a fair balance between these two competing interests, and any inconsistency with Article 11 has to be justified. 
  • Looking at UK domestic law, the fact that an employer can impose any disciplinary sanction it wants (short of dismissal) against a worker who chooses to participate in a lawful strike effectively nullifies the right to strike. Employees cannot strike during working hours without exposing themselves to possible disciplinary action. This absence of protection against detriment means there is no fair balance in UK legislation, which places the UK in breach of its obligations under Article 11. 
  • It is not possible to interpret Section 146 in a way that is compatible with Article 11 of the Convention. Doing so would require the courts to fundamentally change the substance of Section 146, to make a series of policy choices with potentially far-reaching consequences. It would also fundamentally contradict the wording of TULRCA.
  • The wording of Section 146 is inherently objectionable in that, on a conventional interpretation, Ms Mercer is at risk of sanction for exercising her Article 11 right. This means that Section 146 is fundamentally incompatible with Article 11, insofar as it fails to provide any protection against sanctions short of dismissal, intended to deter or penalise trade union members from taking part in lawful strike action. It was therefore appropriate for the Supreme Court to make a declaration of incompatibility

What now?

Clearly, this is a significant win for trade unions and workers who wish to take part in lawful strike action. If TULRCA is amended to be compatible with Article 11 on this point, then striking workers will be able to confidently go on strike during working hours (so long as it is lawful strike action) in the knowledge that they cannot be disciplined by their employer for doing so - no suspensions, no formal warnings, no demotions, etc. Employers may need to rethink their approach to striking workers and will be heavily restricted in terms of the action they can take. Could this decision usher in a new era of increased trade union activity and strike action in the private sector? 

It is important to note that the law has not changed as a result of the Supreme Court’s decision – a declaration of incompatibility does not have the force of invalidating legislation. However, the pressure is now on Parliament to choose whether to address this incompatibility with Article 11 through new/amended legislation; and if so, how, and to what extent. We can envisage a scenario where TULRCA is amended to give striking workers more protection against certain, more severe forms of detriment, but not necessarily all detriment such as withdrawing discretionary benefits. Equally, it would be unsurprising if a new government, especially Labour might choose to use this as an opportunity to overhaul and modernise trade union law. With a general election looming, this could and should be high on the agenda for the new Government. 

In the meantime, employers would do well to rethink their practices to ensure they are not taking formal action disciplinary or otherwise against workers who go on strike. This sort of detriment is now highly vulnerable to legal challenge and carries with it significant reputational risk (as has always been the case). Employers should start preparing for the new, post-Mercer world now, and in the meantime pay a close eye to what Parliament or any new Government does to legislate in this area.