Boris Johnson's controversial plan to override key elements of the Brexit agreement he signed with Brussels has cleared its first Commons hurdle despite deep concerns from some high-ranking Tories.
Two Tory MPs – Sir Roger Gale and Andrew Percy – voted against the bill, while 30 did not vote, although some may have been "paired" with opposition MPs.
The government balance sheet was supported by the support of seven DUP MPs.
The Prime Minister said the legislation was necessary to prevent the EU from interpreting the provisions of the Withdrawal Agreement in relation to Northern Ireland "extremely and unreasonably".
He said some in Brussels are now threatening to block UK agricultural and food exports to the EU and to insist on tariffs on all goods transported to Northern Ireland from the rest of the UK.
However, some senior conservatives warned they could not support the legislation in its current form after ministers admitted last week that it violated international law.
MPs will begin a detailed, line-by-line review of the bill on Tuesday. Votes are expected next week on changes to regulations for Northern Ireland that some Tories may support.
Sir Roger admitted that he was in a "tiny minority" of Conservatives when voting against the bill, but predicted that others might rebel if the Commons ponder the amendments that were tabled.
“I thought you were fighting that tooth and nail every step of the way. Others have made a very clear decision that they want to hold their fire. There's still a lot to play, ”he told BBC2's Newsnight.
Even before the debate started, former Prime Minister David Cameron voiced his "concerns" and former Chancellor Sajid Javid and former Attorney General Geoffrey Cox said they could not support the revocation agreement override.
The intervention of Mr Cameron, who said passing laws in violation of international treaty obligations was "the very last thing you should think about," means that all five living former prime ministers have spoken out against the law.
In the House of Commons, Mr Johnson, who took the unusual step of opening the debate himself, said the "safeguards" were necessary as the EU was now trying to "leverage" the Northern Ireland Protocol in talks on a post-Brexit free trade deal .
He said the Brussels negotiators threatened to ban the sale of British agri-food products anywhere in the EU, creating an "immediate and automatic" ban on the transport of such goods from the UK to Northern Ireland.
"As absurd and self-destructive as this would be in this debate, the EU has still not taken this revolver off the table," he said.
Mr Johnson said some on the EU side even wanted to label all goods transported from the UK to Northern Ireland as "at risk" for entry into the EU's single market, making them subject to EU tariffs.
David Cameron Says He Has "Concerns" About The Bill (Jacob King / PA)
He said this could mean levies of 61% on Welsh lamb, 90% on Scottish beef and 100% on Devonshire clotted cream and "create tariff borders in our own country".
"We cannot have a situation where our country's borders can be dictated by a foreign power or an international organization," he said.
"No British Prime Minister, no government, no parliament could ever accept such an imposition."
For Labor, shadow trade secretary Ed Miliband, who stands for Sir Keir Starmer, who is in coronavirus self-isolation, said Mr Johnson was solely responsible for signing the withdrawal agreement.
"Either he wasn't directly with the country about the deal at all or he didn't get it," said Miliband.
"Because a competent government would never have made a binding agreement with provisions that it could not live with."
A number of Conservative former ministers made it clear that they would not support any measure that violates international law, including Andrew Mitchell, Sir Oliver Heald and another former Attorney General Jeremy Wright.
Sir Charles Walker, vice chairman of the powerful 1922 Tory Backbench committee, and Wakefield MP Imran Ahmad Khan – a member of last year's new Conservative MP – said they would not support the bill at second reading.
Sir Bob Neill, chairman of the Commons Justice Committee, who tabled an amendment requiring a parliamentary vote before ministers can exercise the new powers in the bill, urged MPs to "take the opportunity to amend these clauses and improve ".
Released: from Radio NewsHub