In 2024, the Supreme Court held in the Secretary of State for Business and Trade v Mercer (Mercer) that the protection under section 146 of Trade Union and Labour Relations (Consolidation) Act 1992 (TULRCA) did not extend to detriments for taking lawful industrial action. The government therefore included provision in the Employment Rights Act 2025 (ERA 2025) to protect workers who participate in lawful industrial action from being subject to a detriment.

In our previous article we summarised the options being considered in the government's consultation. In this article we look at the outcome of the consultation, when the changes come into effect and what this means for employers managing employees who take lawful industrial action.

What options did the government consultation consider on protection from detriments for taking industrial action?

The government consulted on two potential options. 

• Option A: whether to prohibit all detriments imposed on a worker for the sole or main purpose of penalising, preventing or deterring them from taking industrial action.
• Option B: a defined list of detriments that employers were prohibited from imposing.

Option A was the government’s preferred option, as there was a concern that a prescribed list may quickly become outdated or inadvertently suggest that anything not on the list was a permitted detriment.

What was the outcome of the consultation?

The government has now published its response which confirms that it intends to proceed with its preferred option A. This approach is consistent with existing protection against detriments for trade union membership or activity under section 146 of TULRCA, which does not limit protection to a subset of detriments.

Regulations to implement the change have been published. If approved the new protections will come into force on 30 October 2026.

Will a deduction from pay be considered a detriment?

A number of respondents to the consultation expressed views that the regulations should expressly provide that proportionate deductions from pay should not constitute a detriment for strikes or other industrial action. However, the government does not believe that this is necessary as it is well established under common law that a worker who declines to work (including by way of strike or other industrial action) is not entitled to pay. This is consistent with the position set out by the Supreme Court in Mercer. Therefore, a proportionate deduction of pay would not amount to a detriment. In addition, the new regulations expressly state that nothing within them affects the common law rules enabling the deduction of pay on account of a worker having taken part in protected industrial action.

Will the Acas Code apply to claims for protection from detriment for taking industrial action?

The government has confirmed that protection from detriment will also be added to the list of claims where compensation may be increased or decreased by up to 25% for any unreasonable failure to follow the statutory Acas Code of Practice on Disciplinary and Grievance Procedures (Acas Code). This is consistent with claims for detriment on grounds related to trade union membership or activity under section 146 of TULRCA 1992. The government expects this approach to promote fair treatment by all parties, as well as more constructive and timely resolutions to disputes.

What does this mean for employers planning how to manage industrial action?

Clarity that the common law position related to deductions of pay will be unaffected by the regulations is welcome. However, there had been calls for clear statutory guidance on what the legislation means in practice, including worked examples of what would and would not fall within scope. Despite this, the government believes that many employers will already be used to applying the 'sole or main purpose' test within the context of section 146 so will be able to use their previous experience to inform their decisions. Therefore, there is no intention to produce statutory guidance although the government has said that gov.uk advice pages on protections from detriments will be updated to reflect the new protections and how they will work in practice. Whilst this may be of some assistance, employers preparing for industrial action will be keen to ensure any measures adopted in response don’t fall foul of the new rules. Undoubtedly there are different considerations which apply to preparation for industrial action that don’t arise in the context of being a trade union member or taking part in trade union activities (both of which are already covered under section 146). For example, if an employer offers overtime post a strike to clear a backlog will it be considered a detriment to offer it employees who did not participate in the strike ahead of those who did?

The burden will be on the employer to show the sole or main purpose for which they acted or failed to act. It will therefore be essential for employers to document the reasons for any action taken in close proximity to the industrial action, such as disciplinary, performance, absence management or denial of training or career progression opportunities. This will enable the employer to evidence that it is unrelated to the participation in the industrial action which will be key in the event a detriment claim is later made.

If you would like to discuss how our team of experienced employment lawyers can support your organisation, please get in touch. You can also find further resources on all things ERA 2025 on our ERA 2025 hub, including our recent podcast on trade union rights of access.