Theresa May is due to make a statement on Brexit to MPs later, which will be followed by a debate on next steps.
MPs are then expected to vote on a series of alternatives to the prime minister’s Brexit deal.
Ministers were feeling “more positive” about being able to hold a third vote on the PM’s deal this week, sources told the BBC’s Laura Kuenssberg.
But Northern Ireland’s DUP has said its position has not changed and it will not be backing the deal.
DUP leader Arlene Foster told the prime minister the news in a telephone call after this morning’s cabinet meeting.
Mrs May’s EU withdrawal agreement has been overwhelmingly rejected in the Commons twice.
She has said she would only bring her deal back for a third Commons vote if there was “sufficient support” for it – and she spent the weekend trying to persuade Brexiteer Tories to get behind it.
But many are thought likely to take their lead from the DUP, which has led objections to the Irish backstop clause.