Peers defeated the government by 433 votes to 165 on Monday night, amending the government’s Internal Market Bill to remove clauses that override the Brexit deal with the EU on Northern Ireland.
Downing Street had already pledged ahead of the vote to use its Commons majority to reinsert the offending clauses, which ministers have admitted break international law in a “limited and specific way”.
But the decision would put Mr Johnson on a collision-course with Mr Biden, who has warned he would not sign a trade deal with the UK if the prime minister presses ahead.
Mr Johnson’s own peers accused him of acting like a common “lawbreaker”, while Labour’s leader in the House of Lords, Baroness Angela Smith, said: “I am sure some in government will initially react with bravado and try to dismiss tonight’s historic votes in the Lords. To do so, however, would underestimate the genuine and serious concerns across the UK and beyond about ministers putting themselves above and beyond the rule of law.
“The government should see sense, accept the removal of these offending clauses, and start to rebuild our international reputation.”
Speaking during the Lords debate on the amendment ahead of the vote, former Conservative leader Lord (Michael) Howard led the calls for Mr Johnson to “think again”.
“What minsters have done, both in your Lordships’s House and elsewhere, is to seek to make the case that circumstances make it expedient to break international law,” the peer, a longtime Eurosceptic and supporter of Brexit, said.
“Isn’t that what lawbreakers always say? Isn’t that the excuse of lawbreakers everywhere? What sort of a precedent is the government setting when it admits that position?
“How can we reproach other countries – Russia, China, Iran – if their behaviour becomes reprehensible when we ourselves have such scant regard for the treaties we sign up to, when we ourselves set such a lamentable example?”
He added: “There have been some suggestions that opposition to this part of the bill is in some way the last charge of the Remainers.
“That suggestion has a very dangerous implication for those who advance it. It implies that only those who voted for us to Remain in the European Union care about the rule of law, or the importance of keeping one’s words, or the sanctity of international treaties.
“Fortunately, I am in a position which enables me confidently to contradict that implication. I voted and campaigned for Brexit and I do not for one moment regret or resile from that vote.
“But I want the independent sovereign state that I voted for to be a country which holds its head up high in the world, that keeps its word, that upholds the rule of law and that honours its treaty obligations.”
Crossbench peer Lord Judge, a former head of the judiciary, warned that peers should be “neither complicit nor supine” and should vote against clauses in the bill.
The Archbishop of Canterbury Justin Welby also weighed in, arguing that the bill “fails to take into account the sensitivities and complexities of Northern Ireland and could have unintended and serious consequences for peace and reconciliation”.
The clauses would effectively ban the imposition of checks and controls on trade between Northern Ireland and Great Britain, despite the fact that the government signed up to them in the withdrawal agreement with the EU.
Another clause would also ban courts from reviewing the legislation, which former Supreme Court justice Lord Neuberger said last month would put Britain on a “very slippery slope” towards a dictatorship.
The European Commission, with which the UK is currently negotiating a free trade agreement, has also said the clauses need to be removed, and launched an infringement procedure against the UK at the European Court of Justice.
