The UK could pursue alternative options if Theresa May's Brexit plan is rejected by MPs, a UK cabinet minister has said.
Amber Rudd, the Work and Pensions Secretary for the UK, became the first cabinet minister to publicly discuss the merits of a "Plan B" if Mrs May crashes to defeat in Tuesday's crunch Commons vote.
She also suggested a second referendum was another potential outcome that might be sought by MPs if the deal is thrown out.
Ms Rudd told The Times that, should the deal be voted down, she would prefer a so-called Norway-plus model for Brexit that would involve staying part of the European Economic Area.
The former home secretary said the alternative "seems plausible not just in terms of the country but in terms of where the MPs are," but conceded that "nobody knows if it can be done".
Ms Rudd predicted a "chaotic" period if the British government is defeated.
"If it doesn't get through, anything could happen - People's Vote, Norway-plus, any of these options could come forward and none of them are as good as the current arrangement we have got with the Withdrawal Agreement to vote on on Tuesday."
Her comments could be viewed as an attempt to win over Brexiteers who might prefer Mrs May's deal, even with its controversial Northern Irish backstop, to a Norway-plus future inside both the single market and customs union or the possibility of another referendum reversing the 2016 vote.
"A lot of people have a perfect vision of what they think Brexit should look like, and that 'perfect' is not available," she told BBC Radio 4's Today.
"What we need is a compromise deal, that's what the Prime Minister has proposed and I would urge my colleagues to think about, first of all, why people voted to leave the European Union, what their interpretation is of that; and secondly, what the alternatives are.
"This is why I think it is important for people not just to think why they don't particularly like the Withdrawal Agreement but what they would like better that is available and would get through the House of Commons."
Mrs May was warned by critics that she could be forced to stand down as British Prime Minister if her Brexit deal is defeated in the Commons next week.
Eurosceptic former party leader Iain Duncan Smith cautioned against the PM and her Cabinet deciding to "brazen it out", saying such an approach would be a "disaster".
"How the PM responds after the vote matters more than anything else she has done," he told the Daily Telegraph.
"I believe that if the response is, 'we've lost but we will do this all over again', it will become a leadership issue."
Another former leader Lord Howard said Mrs May would have "difficult decisions to make about her future and about the future of our country" if she loses on December 11.
Ms Rudd said she hoped the UK government would "regroup" and "hold stable, hold firm" in the aftermath of a defeat.
"What would be a complete mistake would be to allow what is already an unstable period to descend into further instability with talk of a leadership change," she said.
The cabinet minister also appeared to endorse an amendment to the government's motion for the vote on Tuesday tabled by former Northern Ireland minister Sir Hugo Swire in an attempt to win over wavering Eurosceptics.
The alteration would mean UK Parliament would have to approve a decision to trigger the backstop arrangement, put a one-year time limit on it and seek assurances from the EU that the backstop would be temporary.
Ms Rudd told Today: "Hugo Swire has put an amendment down which I hope will give some of my colleagues reassurance over the so-called backstop."
Lord Howard suggested that talks with Brussels should be intensified to prepare for a Brexit with no formal deal.
"We should seek to put in place some ad hoc, temporary arrangements with the agreement of the European Union which would minimise and, indeed, perhaps even eliminate any disruption at the border on March 30 next year," he told Today.
"We should also undertake that we would unilaterally, for the period of 12 months after March 29, allow any goods and services in from the European Union without any tariffs or tariff barriers or obstacles in any way - hope that they will reciprocate but do it even if they don't - and use that 12-month period to negotiate a free-trade agreement along the style of Canada-plus."
Former Brexit secretary David Davis warned the Tory leadership not to attempt to "bully" MPs into supporting a "failed strategy".
"Our role is to come together to find a joint approach that supports the decision of the referendum and promotes the national interest," he said.
Meanwhile, UK Labour leader Jeremy Corbyn said he would consider delaying Britain's exit from the EU to negotiate a better deal if his party came to power.
"If we go into government straight away we would start negotiating straight away. If it meant holding things a bit longer to do it, of course," he told Sky News.
Mr Corbyn said his party was ready to "step in and negotiate" with the EU and would form a minority government "if that is what is on offer".
'Brexit Betrayal' March
Ahead of the commons showdown, controversial activist Tommy Robinson will lead a pro-Brexit march in London on Sunday - with a rival counter-demonstration set to oppose it.
The English Defence League (EDL) founder, who provoked prominent Ukip figures to desert the party after he was made an adviser, is to rally with supporters in London on Sunday.
The so-called Brexit betrayal march organised by Ukip will be opposed by Labour-backed campaigners and anti-fascist groups, with police imposing restrictions amid fears of violence.
Shadow chancellor John McDonnell urged Labour supporters to march against the "poison" of Mr Robinson, whose real name is Stephen Yaxley-Lennon.
"This march isn't about Brexit, it's about far-right extremists dressing up in suits and pretending to be respectable," Mr McDonnell said.
"A newly energised, well-funded network of hate is emerging, from (former Donald Trump strategist) Steve Bannon in the US to the former EDL leader Tommy Robinson at home, and it threatens the very fabric of our nation."
Among those marching against the activist are grass roots group Momentum and Unite Against Fascism.
Police have heightened concerns after "serious violence" broke out at a Robinson rally in London in June, with five officers injured when bottles and barriers were hurled at them.
Scotland Yard said it also imposed the conditions based on the "current intelligence picture".
Gathering outside the Dorchester Hotel, Mr Robinson's supporters must march along a specified route from Park Lane to Parliament Street.
There, police barriers will separate them from counter-demonstrators who must march from outside the BBC building in Portland Place to Whitehall.
Nick Lowles, chief executive of anti-racism campaigners Hope Not Hate, was among those critical of Mr Robinson's rally.
"This is a cynical attempt by some of the most extreme voices in Britain, united in hatred for Muslims and other minorities, to exploit Brexit tensions and sow discord and hatred, much as Gerard Batten has done with Ukip and its Islamophobic charge to the right since he took over," he said.
Elsewhere in the capital, the pro-EU Best for Britain and second referendum campaign People's Vote will hold a rally featuring politicians including Lord Heseltine and celebrities such as actors Charles Dance and Jason Isaacs.