The European Commission said on Thursday it would consider its next steps - which could include taking Britain to the European Court of Justice - after the British government responded to its legal challenges over post-Brexit trade for Northern Ireland.
The European Union executive had given Britain until Thursday to respond to three infringement procedures, which the Commission said Britain had now done.
"We will now analyse the reply before deciding upon next steps," a spokesperson said at the Commission's regular daily news conference, without giving details of the reply.
British officials have said they want to keep the status quo, including grace periods for various checks on goods shipped from the British mainland to Northern Ireland.
Because of its open land border with EU member state Ireland, the British province has remained in the EU single market for goods after Brexit, meaning imports from the rest of the United Kingdom are subject to customs declarations and sometimes require checks on their arrival.
The arrangement, set to avoid reinstating border controls between Northern Ireland and Ireland, has inflamed pro-British unionist parties by effectively creating a border in the Irish Sea between the island of Ireland and the British mainland.
Britain's Conservative government has said the protocol governing trading arrangements should be renegotiated and is pushing forward a bill that would scrap most checks by disapplying parts of the protocol.
The EU has said that unilaterally changing an international agreement, which was approved by then-Prime Minister Boris Johnson's government in 2019, is unjustified and illegal.
The three legal proceedings do not relate to Britain's new plans, but to the EU belief that Britain is not implementing the protocol, such as by failing to carry out required checks and ensure adequate staff and infrastructure to do so.
(Reporting by Philip Blenkinsop, additional reporting by Elizabeth Piper in London, editing by Mark Heinrich)
