Unionist parties in the Northern Ireland Assembly have formally asked the UK government to pull the Stormont Brake to block changes to European Union customs rules. It is only the second time politicians have sought to use the mechanism since it was created under the 2023 Windsor Framework.

Assembly Speaker Edwin Poots has written to the Secretary of State for Northern Ireland, Sir Chris Bryant, who must now decide whether the legal tests for triggering the brake have been met. The formal notification was signed by MLAs from the Democratic Unionist Party, the Ulster Unionist Party, Traditional Unionist Voice and independent unionist Claire Sugden, the Assembly confirmed.

The objection concerns a major overhaul of the EU customs code, under Regulation (EU) 2026/2108, the new Union Customs Code. Unionist parties argue the new code would deepen the customs border in the Irish Sea and impose fresh financial and technical burdens on smaller firms, which would need to update software and integrate with EU systems.

The case faces a high bar. A report by the Assembly's Windsor Framework committee last month found the changed rules would not have a significant impact specific to everyday life of communities in Northern Ireland in a way that is liable to persist. The brake can only be used where at least 30 MLAs from two or more parties support the objection and the statutory tests are met.

One flashpoint has already been defused: a potential two euro handling charge on parcels sent from Great Britain to Northern Ireland was avoided after a UK-EU agreement. If Sir Chris Bryant judges that the tests have been met, the UK would notify the EU, opening intensified consultation in the Windsor Framework Joint Committee. Read the BBC's report here.