Former British foreign secretary Boris Johnson has said Prime Minister Theresa May should go back to Brussels and tell EU negotiators that the UK would not accept the backstop arrangement.
He insisted there was no danger of a hard border as neither the Irish or British governments wanted to erect one.
Answering questions following a speech at JCB headquarters in Staffordshire, Mr Johnson said the "unprecedented" 230-vote defeat of the Withdrawal Agreement in the House of Commons had given Mrs May a "mandate".
"She can go back to Brussels, and she should go back to Brussels and say that the British House of Commons doesn't accept the democratic consequences of the arrangement you have imposed in the form of the backstop," he said.
"It's got to come out."
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Mr Johnson called on the British government to "use Brexit to unite the country" and focus on the issues that drove the vote for EU withdrawal.
He said Brexit was about democracy.
"But that vote was also triggered by a feeling that, in some way, the people of this country have been drifting too far apart and in areas where we need to come together."
The move follows a bid by Mrs May to talk to prominent MPs and opposition leaders about Brexit in the wake of the government's crushing Commons defeat, a change of political tack that Labour leader Jeremy Corbyn branded a "stunt"
Asked whether he would back Mrs May to lead the Conservatives into a snap election if one was called, Mr Johnson said: "I think most people in this country feel they have had quite enough elections. I certainly do.
"I think it highly unlikely that that would be the outcome. A snap election is not the right way through."
Mr Johnson, who was the figurehead of Vote Leave in the 2016 referendum, attempted to distance himself from the campaign's claims about immigration from Turkey.
Vote Leave produced adverts posted widely on social media during the campaign that stated that "Turkey (population 76 million) is joining the EU" and "Britain's new border is with Syria and Iraq".
Some of the ads included images of people in Turkey with large red arrows pointing towards the UK.
Challenged over the campaign ads, Mr Johnson said: "I didn't say anything about Turkey in the referendum ... Since I made no remarks, I can't disown them."
When it was put to him that he was the leader of the Vote Leave campaign, he replied: "You do me too much honour.
"I was happy to support Leave and I do and I did. I happen to think that immigration can be a wonderful thing for our country, but as I've said time and time again, it's got to be controlled."
With Mrs May set to present a Brexit Plan B to the Commons on Monday, Labour former prime minister Gordon Brown used a speech in Edinburgh yesterday to call on the government to extend Article 50 by a year in order to consult the public.
Mr Brown said Mrs May's Brexit stalemate has left Britain "more divided than during the three-day week of the 1970s or during the miners' strike of the 1980s".
Mrs May will be meeting with "a large number" of Cabinet ministers in Downing Street today, a No 10 spokeswoman said.
The meetings will be both with individual ministers and in groups throughout the day, the spokeswoman added, but there will not be a "cabinet gathering as such".
She declined to give a list of names but said that more than half of cabinet ministers would be attending.
The spokeswoman added: "I'm sure they will discuss a wide range of issues but you can expect Brexit to be a dominant focus."
She said that the prime minister had held "constructive" telephone conversations with German Chancellor Angela Merkel and Dutch Prime Minister Mark Rutte yesterday.
Mrs May will also speak with European Commission President Jean-Claude Juncker today.
A spokesman for the European Commission said: "At her request, President Juncker will talk to Prime Minister May today, early afternoon."
Mrs May will not be attending the Davos summit in Switzerland next week, Downing Street confirmed.
Mr Corbyn said he would not take part in the Brexit talks as Mrs May would not take a no deal option off the table.
Downing Street said it is "impossible" for the government to rule out a no-deal Brexit as such a move could only be done by securing parliamentary approval.
However, the Daily Telegraph reported that up to 20 middle ranking ministers could resign unless they are given a free vote on a backbench bid to rule out a no-deal exit from the EU.
And, according to the Guardian, Mr Corbyn faces up to a dozen resignations from his front bench if he comes out in favour of a second Brexit referendum.
Meanwhile, former Ukip leader Nigel Farage said Brexiteers should get ready for the possibility of a second referendum.
He told a Leave Means Leave gathering in Westminster: "Let us prepare, let us organise.
"If I have to fight again against this lot, then believe me, next time, as far as I'm concerned, it's no more Mr Nice Guy."
