Video report by ITV News Political Correspondent Paul Brand
Theresa May has urged MPs to give a “second look” to her Brexit deal before Tuesday's crunch vote in the House of Commons.
The Prime Minister asked MPs to think about how history will judge them if they do not back her deal.
Speaking in the House of Commons, she said: “When the history books are written, people will look at the decision of this House tomorrow and ask: did we deliver on the country's vote to leave the European Union? Did we safeguard our economy, our security and our Union? Or did we let the British people down?”
Mrs May warned any move by MPs to prevent the UK leaving the EU would be a "subversion of democracy" and, while she acknowledged that the Withdrawal Agreement was "not perfect", she urged MPs on all sides to give it a "second look".
In a last-ditch appeal, Mrs May later warned a private meeting of Conservatives that defeat in Tuesday's crunch vote could hand the keys of No 10 to Jeremy Corbyn.
ITV News Political Editor Robert Peston said he expects Mrs May to lose by more than 100 votes.
The deal suffered its first official parliamentary defeat in the House of Lords on Monday night as peers voted by 321 votes to 152 - a majority of 169 - to reject it.
In the Commons, the Labour leader said Mrs May had failed to secure the assurances she had promised and the Government was in "disarray".
"It's clear, if the Prime Minister's deal is rejected tomorrow, it's time for a general election, it's time for a new government," he said.
Earlier in a statement on Monday at a factory in Stoke-on-Trent, the Prime Minister reiterated "the only deal on the table is the one that MPs will vote on tomorrow night."
"You can take no deal off the table by voting for that deal and if no deal is as bad as you believe it is - it would be the height of recklessness to do anything else.
"While no deal remains a serious risk, having observed events at Westminster over the last seven days, it's now my judgement that the more likely outcome is a paralysis in parliament that risks there being no Brexit."
But many on both sides of the debate have already made their position clear – they intend to vote down her withdrawal agreement.
Following her speech, the Conservative MP for Dartford, Gareth Johnson, resigned as a Government whip in order to oppose her deal.
Earlier, her former foreign secretary Boris Johnson told reporters that “we should vote down this deal in the absolute confidence that it is the right thing to do”.
European Commission president Jean-Claude Juncker and European Council president Donald Tusk released a letter on Monday offering “clarifications” to the deal that Brussels “does not wish to see the backstop enter into force” and confirming its “determination” to see it replaced.
The letter states that "we are not in a position to agree to anything that changes or is inconsistent with the Withdrawal Agreement".
It added further clarification that there is a "commitment to work speedily on a subsequent agreement that establishes by 31 December 2020 alternative arrangements, so that the backstop will not need to be triggered."
Mrs May referenced historic devolution votes in her speech as justification to push ahead with her deal.
“Imagine if an anti-devolution House of Commons had said to the people of Scotland or Wales that despite voting in favour of a devolved legislature, Parliament knew better and would overrule them. Or else force them to vote again", the Prime Minister is expected to say.
“What if we found ourselves in a situation where Parliament tried to take the UK out of the EU in opposition to a remain vote?””
“We all have a duty to implement the result of the referendum.
However, ITV News political correspondent Paul Brand pointed out a second referendum on scrapping the Welsh assembly was a Conservative Party pledge as late as 2005.
Mrs May said that while the two sides in the 2016 referendum disagreed on many things, they were united on one thing – that “what the British people decided, the politicians would implement”.
“On the rare occasions when Parliament puts a question to the British people directly we have always understood that their response carries a profound significance."
“When the people of Wales voted by a margin of 0.3%, on a turnout of just over 50%, to endorse the creation of the Welsh Assembly, that result was accepted by both sides and the popular legitimacy of that institution has never seriously been questioned.
“Parliament understood this fact when it voted overwhelmingly to trigger Article 50. And both major parties did so too when they stood on election manifestos in 2017 that pledged to honour the result of the referendum.”