Former Tory PM Sir John Major has blasted the Government over its plans to flout international law by overriding key parts of the Brexit deal.
The Tory grandee warned the decision to rejig parts of the agreement with the EU could undermine the UK’s global standing.
Amid a furious backlash at home and abroad, Boris Johnson vowed to press ahead with controversial legislation allowing the UK to unpick parts of the treaty negotiated last year.
The Prime Minister said the new Internal Markets Bill – tabled in Parliament on Wednesdy – was needed to provide a “legal safety net” to protect peace in Northern Ireland in case of a no-deal Brexit.
But Sir John criticised the move, saying: “For generations, Britain’s word – solemnly given – has been accepted by friend and foe. Our signature on any treaty or agreement has been sacrosanct.
“If we lose our reputation for honouring the promises we make, we will have lost something beyond price that may never be regained.”
His comments followed a rare intervention from ex-PM Theresa May, who accused Mr Johnson in the Commons of undermining trust as the UK prepares to strike out on its own after Brexit.
EU chiefs demanded urgent talks with Britain following the publication of the bill on Wednesday, which Tory ministers admitted would breach international law in a “very specific and limited” way.
European Commission boss Ursula von der Leyen said she was “very concerned about announcements from the British government on its intentions to breach the Withdrawal Agreement”.
“This would break international law and undermines trust,” she said.
EU Brexit negotiator Michel Barnier arrived in London for a fresh round of negotiations as tensions exploded over the move, which threatens to torpedo trade talks as the clock ticks towards the end of the transition period in December.
The row comes after Mr Johnson repeatedly boasted that his Brexit deal was “oven ready” as part of his election pledges to “get Brexit done”.
But Downing Street suggested that the deal had been rubber-stamped too quickly.
The PM’s official spokesman said it had been agreed “at pace in the most challenging political circumstances”, meaning last-minute changes were needed to iron out “ambiguities”.
The new bill allows the UK to ditch EU rules over customs checks on goods travelling between Northern Ireland and the UK if trade talks fail – with a similar principle applying to state aid.
On Wednesday, Matt Hancock said he was comfortable with the Government breaking the law over Brexit – but dismissed the idea that the public was allowed to break social distancing rules if the Government flouts international law.
Questions have been raised over the future of Justice Secretary Robert Buckland and Attorney General Suella Braverman after the Government’s top legal official quit earlier this week in protest at the decision to water down parts of the Brexit treaty.
Labour called for Mr Buckland to intervene to enforce the rule of law.
Shadow Justice Secretary David Lammy wrote to the top Tory, saying: “What steps do you plan to take to protect the rule of law from attack from inside your own government?
“If you fail to prevent the government from breaking the rule of law, will you stand by your oath to respect the rule of law by breaking cabinet responsibility on this matter?”
A source close to Mr Buckland said he would not be resigning.