The chances of Britain leaving the European Union will be little more than “50-50” if Theresa May’s Withdrawal Agreement is rejected by MPs, Cabinet Brexiteer Liam Fox has said.

Dr Fox told the Sunday Times that Brexit will only be “100% certain” if the House of Commons backs the Prime Minister’s deal in a crunch vote next month.

The International Trade Secretary warned fellow MPs that failure to pass May’s deal would be “incendiary” and said it was “a matter of honour” for them to support the PM.

Having given the public the right to decide on EU membership in a referendum, “Parliament cannot now, with any honour, renege on that result”, said Dr Fox.

“Were they to do so, I think you would shatter the bond of trust between the electorate and Parliament. And I think that would put us into unprecedented territory with unknowable consequences.”

Campaigners for a second EU referendum seized on the International Trade Secretary’s comments, saying that polls suggested that fewer than 50% of Britons now want to leave the EU.

Liberal Democrat MP Layla Moran, a leading supporter of the Best for Britain campaign for a referendum, said: “Brexit not happening isn’t 50-50 as Liam Fox says. It’s actually 56-44.

“That’s the way the public now feels about us stopping this badly-led disaster and strengthening ourselves within the EU.

“The only thing that is shattering the bond of trust between electorate and Parliament is the refusal of ministers like Liam Fox to trust people with the final say on Brexit.”