Theresa May has asked MPs to make an “honourable compromise” as she seeks to persuade them to back her Brexit deal at the third time of asking.
Writing in the Sunday Telegraph, the prime minister said failure to support the deal would mean “we will not leave the EU for many months, if ever”.
Mrs May is expected to bring her withdrawal agreement back to the Commons next week for a third vote.
It comes after MPs this week rejected her deal and voted to delay Brexit.
Former Cabinet minister Esther McVey, who resigned over the Brexit agreement, told Sky’s Sophie Ridge programme that she would “hold my nose” and vote for the deal after rejecting it twice herself, as it was now a choice between “this deal or no Brexit”.
And a letter signed by 15 Tory MPs from Leave-backing constituencies, including former Brexit Secretary David Davis, also urged colleagues to back the deal.
But International Trade Secretary Liam Fox warned the vote could be pulled, telling Sophie Ridge it was “difficult to justify having a vote if we knew we were going to lose it”.
The EU will decide the terms and conditions of any extension. Legally, the UK is still due to leave the EU on 29 March.