Theresa May has rejected alternatives to her Brexit deal, urging MPs to think about the consequences for their constituents of voting it down.
The PM, who is in Argentina for a G20 summit, ruled out moving to Norway-style deal with the EU, an idea being promoted by some Tory MPs.
She said this was unacceptable as it would see freedom of movement continue.
Labour argues a better deal could still be done but the PM has said they have not put forward a proper alternative.
By threatening to oppose her deal in a Commons vote on 11 December, Mrs May said Labour were effectively advocating leaving without a deal.
The Labour leadership has said it is ready to support a cross-party amendment to the vote that would rule out no-deal.
The amendment would not be binding but it would be hard for the PM to ignore it, if it is passed by Parliament.
Leading Tory Brexiteer Jacob Rees-Mogg has, meanwhile, warned against efforts to “frighten” people into backing what he called “a non-Brexit Brexit”, in the Daily Telegraph.
It is widely expected that MPs will reject it the EU withdrawal agreement and blueprint for a future trade deal agreed with the EU on 11 December.
But speaking to reporters on her flight to Buenos Aires, Mrs May insisted she had not given up hope of winning the vote.
If MPs failed to back her it would mean “division and uncertainty” for Britain, she warned.
“Let’s focus on the deal that we have negotiated with the EU, a deal which is good for the UK and good for their constituents,” she said.
Mrs May said people she had met outside Westminster in the last few days had given her an “overwhelming” sense that they wanted MPs to back her deal.