There's a 50-50 chance that Brexit may be stopped if the government rejects the European Union withdrawal deal next month, trade secretary Liam Fox said.
"If we were not to vote for that, I'm not sure I would give it (Brexit) much more than 50-50," Fox told the Sunday Times newspaper.
The United Kingdom is due to leave the EU on 29 March 2019 and a vote on the divorce deal is set to take place in the week starting 14 January.
Prime Minister Theresa May called off a vote earlier this month after concerns it would be rejected "by a significant margin."
Fox, one of the most senior pro-Brexit politicians in the British cabinet, said the only way to be "100% certain" that Britain will leave the EU is if politicians vote for May's deal.
He added that voting against it would "shatter the bond of trust between the electorate and parliament."
The international trade minister said he would prefer a deal that falls short than risk "no Brexit."
It comes after Fox pleaded for other MPs to back May's withdrawal agreement in a speech in Bristol last month.
“In politics we cannot always have the luxury of doing what we want for ourselves, but we have an abiding duty to do what is right for our country,” he said during that speech.