The government has suffered a defeat in the House of Lords over its controversial Brexit legislation.
The Internal Market Bill contains measures that overrule parts of the UK’s Brexit agreement with the EU.
Peers voted overwhelmingly to remove a section of the bill that would allow ministers to break international law – by 433 votes to 165.
The government said it would reinstate the clauses when the bill returns to the House of Commons next month.
It comes as trade talks continue between EU and UK officials in London as they try to reach an agreement over a future economic partnership.
A government spokesman said in a statement: “We will retable these clauses when the bill returns to the Commons.
“We’ve been consistently clear that the clauses represent a legal safety net to protect the integrity of the UK’s internal market and the huge gains of the peace process.
“We expect the House of Lords to recognise that we have an obligation to the people of Northern Ireland to make sure they continue to have unfettered access to the UK under all circumstances.”
The Internal Market Bill is designed to enable goods and services to flow freely across England, Scotland, Wales and Northern Ireland after 1 January – when the post-Brexit transition period runs out.
It gives the government the power to change aspects of the EU withdrawal agreement, a legally binding deal governing the terms of Brexit made earlier this year.
UK’s five living former prime ministers – Sir John Major, Tony Blair, Gordon Brown, David Cameron and Theresa May – have all spoken out against the bill.
Labour, the Liberal Democrats, the SNP and the EU argue that – in allowing the government to undo parts of a treaty signed by the EU and UK – it could damage the country’s international reputation and standing.