The Northern Ireland secretary has admitted Boris Johnson’s plan to table legislation to override the Brexit deal he agreed with the EU will break international law.
Brandon Lewis said the proposal will “break international law in a very specific and limited way”.
He added that “there are clear precedents for the UK and indeed other countries needing to consider their international obligations as circumstances change”.
Video: Northern Ireland Secretary on Brexit Bill
The government said on Monday it would introduce a new UK Internal Market Bill which could change Northern Ireland’s customs and trade rules post Brexit.
The EU has warned Britain its international reputation would be tarnished and there would be no trade deal if it tried to undercut the Brexit Withdrawal Agreement signed, in January in relation to the protocol for Northern Ireland.
No 10 said it was committed to the treaty but that it needed minor clarifications and a backup plan to support the 1998 Northern Ireland peace deal.
Former prime minister Theresa May warned “trust” in the UK would be damaged if the country reneged on the deal.
In an intervention in the Commons, she asked how the UK "can be trusted" by its allies if the initial agreement was not adhered to.
She said: “Given that, how can the government reassure future international partners the UK can be trusted to abide by the legal obligations of the agreements it signs.”
Shadow Northern Ireland secretary Louise Haigh called the admission from Lewis “astonishing”.
She tweeted: “Absolutely astonishing that the Secretary of State for Northern Ireland has confirmed the government WILL be in breach of international law by undermining the Northern Ireland Protocol.
“This seriously undermines our authority on the international stage.”
Watch: What is the latest disruption to hit the Brexit trade negotiations?
Housing secretary Robert Jenrick said on Tuesday unless the EU started to show more flexibility to help clinch a Canadian-style free trade deal then the government would be happy to leave the bloc without a deal.
"We want to leave with a Canada-style free trade arrangement – that's always been our preference – and we think that's still possible," he told Sky News.
“But... if they don't show the degree of flexibility and realism that we want them to show... then we'll leave with the kind of trading arrangements that Australia and other countries have and we think that's also a good arrangement for the future.”
The UK left the EU on 31 January but talks on new trade terms have made little headway as the clock ticks down to an October deadline and then the end of the status-quo transition arrangement in late December.