Secretary of State for Business and Trade v Mercer

Factual and Procedural Background

The Appellant was employed as a support worker by Company A and acted as a workplace representative for the Union. In early 2019 the Union organised lawful strike action over proposed changes to pay. The Appellant helped plan and joined the strikes. Company A suspended her, continued ordinary pay but withheld overtime, and later pursued disciplinary proceedings. The Appellant lodged a tribunal claim under section 146 of the Trade Union and Labour Relations (Consolidation) Act 1992 (“TULRCA”), alleging the suspension was intended to deter participation in lawful industrial action.

Proceedings were limited to a preliminary legal question: does section 146 protect workers from detriments short of dismissal when they take lawful strike action? Judge Franey (Employment Tribunal) answered “no”. Judge Choudhury (Employment Appeal Tribunal) reversed that decision, reading words into TULRCA to extend protection. The Defendant successfully appealed to the Court of Appeal, which reinstated the original view and declined to issue a declaration of incompatibility. The Appellant obtained permission to appeal to the Supreme Court.

Legal Issues Presented

1. Whether Article 11 of the European Convention on Human Rights (“ECHR”) obliges the United Kingdom to protect union members from employer sanctions short of dismissal for taking part in lawful strike action.
2. Whether, applying section 3 of the Human Rights Act 1998 (“HRA”), section 146 TULRCA can be interpreted compatibly with Article 11 to provide such protection.
3. If a compatible interpretation is impossible, whether the courts should grant a declaration of incompatibility under section 4 HRA in respect of section 146.

Arguments of the Parties

Appellant's Arguments

• Strasbourg jurisprudence treats any sanction intended to deter lawful strike action as an unjustified interference with Article 11; therefore national law must forbid all such detriments.
• Section 146 is the only domestic vehicle capable of giving effect to this protection and can be read down by adding a new limb to the definition of “appropriate time,” confined to “protected industrial action.”
• If reading-down is impossible, section 146 is intrinsically incompatible with Article 11 and a declaration of incompatibility should be issued.

Defendant's Arguments

• Article 11 does not require blanket protection against every detriment imposed by private employers; the United Kingdom enjoys a wide margin of appreciation in balancing competing interests.
• Altering section 146 would require extensive policy choices—effectively judicial legislation—so a compatible construction is impossible under section 3 HRA.
• Any incompatibility arises, if at all, from a legislative lacuna rather than a defect in a specific provision; therefore a declaration of incompatibility should be refused.

Table of Precedents Cited

Court's Reasoning and Analysis

Domestic construction. Citing Drew v St Edmundsbury BC, the Court reaffirmed that the phrase “activities of an independent trade union” in sections 146 and 152 has, for decades, been read as excluding participation in industrial action because the protection is confined to activities undertaken “at an appropriate time” (i.e. outside working hours or within them with the employer’s consent). Extending section 146 to cover strike action would collide with the parallel, tightly delimited dismissal regime in Part V of TULRCA and render it redundant.

Legislative history. A survey from the Industrial Relations Act 1971 through successive consolidations showed that Parliament has consistently separated protection for ordinary union activity (limited to “appropriate time”) from the more restricted and variable protection for striking employees. That history indicated a deliberate legislative design.

Article 11 analysis. The Court accepted that lawful strike action is protected by Article 11, but—drawing heavily on RMT and related Strasbourg authorities—held it is not a “core” or “essential” element of union freedom. Consequently, the State enjoys a wide margin of appreciation when regulating employer reactions. Nevertheless, providing no statutory safeguard against any detriment short of dismissal fails to strike a fair balance and places the UK in breach of its positive obligation under Article 11.

Section 3 HRA. Invoking the limits elaborated in Ghaidan, Sheldrake and others, the Court found that reading words into section 146 would require choosing among multiple policy options (e.g. scope, duration, treatment of workers versus employees). Such choices would contradict a fundamental feature of TULRCA and amount to impermissible judicial legislation.

Section 4 HRA. Although the Court of Appeal viewed the problem as a mere statutory “lacuna,” the Supreme Court ruled that section 146 itself legitimises employer sanctions and therefore is the incompatible provision. Given the absence of pending legislation and the need for Parliament to craft an appropriate scheme, a declaration of incompatibility was both available and appropriate.

Holding and Implications

HOLDING: The appeal is allowed to the extent that the Court issues a declaration, under section 4 Human Rights Act 1998, that section 146 TULRCA is incompatible with Article 11 ECHR insofar as it fails to protect workers from sanctions short of dismissal imposed for participating in lawful strike action.

Implications: The ruling does not itself amend TULRCA; section 146 remains in force until Parliament legislates. However, the declaration formally notifies the legislature that the current scheme breaches Convention obligations, prompting potential reform to extend protection against employer detriments during lawful industrial action. No new common-law right was created, and individual remedies depend on future legislative change or recourse to Strasbourg.