Britain's government on Thursday defied threats from the European Union of legal action over contentious Brexit legislation, and pushed back against a brewing revolt within its own ranks for violating the binding divorce treaty.
The UK bill has further complicated the already messy Brexit process, as Britain unpicks nearly 50 years of European integration, and European Commission vice president Maros Sefcovic rushed to London to demand clarification.
The new bill's potential implications for Northern Ireland -- which is meant to enjoy a special status after Brexit -- also prompted a threatening reminder from powerful US Democrat Nancy Pelosi for London to uphold the troubled territory's peace process.
Serving MPs and grandees of Prime Minister Boris Johnson's Conservatives, including former prime minister John Major and ex-party leader Michael Howard, issued their own sharply-worded reminders that the rule of law is sacrosanct.
"How can we reproach Russia or China or Iran when their conduct falls below internationally accepted standards, when we are showing such scant regard for our treaty obligations?" Howard told the upper chamber House of Lords.
At the meeting, Sefcovic told senior British minister Michael Gove that unless the measures were withdrawn "by the end of the month", Brussels would consider going to court.
The European Commission warned that Britain "has seriously damaged trust between the EU and the UK", and scorned Downing Street's contention that the bill will preserve the peace in Northern Ireland.
"In fact," the statement said, Brussels "is of the view that it does the opposite".
The British government, however, signalled no retreat.
"I made it perfectly clear to the vice president Sefcovic that we would not be withdrawing this legislation and he understood that. Of course he regretted it," Gove said.
Asked about the mounting disquiet in Conservative ranks, he said all sides would get a chance to review the bill in parliament next week, and said it was "critical" for businesses and peace in Northern Ireland.
- Rush job? -
The bill would give British ministers unilateral powers to regulate trade among England, Scotland, Wales and Northern Ireland, once the force of EU law expires after a post-Brexit transition period at the end of this year.
But under the EU withdrawal treaty, Britain is meant to liaise with Brussels on arrangements for Northern Ireland, which will have the UK's only land border with the EU, and where 30 years of bloodshed ended with a historic peace deal in 1998.
France told Britain it was "unacceptable" to violate the EU treaty, and the pound slumped further on currency markets with businesses growing ever-more alarmed that the coronavirus-hit UK economy could fall off a Brexit cliff edge at the end of this year.
Irish premier Micheal Martin, who spoke by phone with Johnson on Wednesday evening, said such an outcome would be "gross irresponsibility" on top of the economic havoc inflicted by Covid-19.
EU officials -- and Johnson's opponents at home including in the UK's devolved governments -- have ridiculed Downing Street's argument that the treaty was written "at pace" and contained unforeseen problems relating to a protocol on Northern Ireland.
But the British government published a legal position to spell out its belief that, notwithstanding any binding promises to the EU, "parliament is sovereign as a matter of domestic law and can pass legislation which is in breach of the UK's treaty obligations".
- 'No chance' -
Sefcovic and Gove met on the last day of a parallel track of talks in London this week over a future trading relationship between Britain and the European Union.
EU chief negotiator Michel Barnier said Britain was still failing to move on key areas and "significant differences remain".
His UK counterpart, David Frost, said its position had always been clear and it had "engaged in discussions in all areas".
Both said they remained committed to securing a deal.
Johnson's critics say the new bill is aimed partly at torpedoing the trade talks, so Britain can go its own way and forge other deals free from EU interference, not least with the United States.
However, House of Representatives Speaker Pelosi gave short shrift to any hopes of Congress ratifying a future trade deal if Britain ploughs ahead with the new Brexit bill.
The top-ranking Democrat said London must respect the EU treaty's Northern Ireland Protocol, which envisages borderless trade with EU member Ireland in compliance with the 1998 peace pact.
"If the UK violates that international treaty and Brexit undermines the Good Friday accord, there will be absolutely no chance of a US-UK trade agreement passing the Congress," she warned.