In a stark warning, former Brexit minister Steve Baker said the Conservative Party faces a "catastrophic split" if Theresa May sticks to her Chequers plan for future relations with the EU.

The comments came amid open warfare in the Tory ranks after former foreign secretary Boris Johnson's likened the government's Brexit strategy to placing the UK in a "suicide vest" and handing Brussels the detonator.

Baker, who quit in response to May's plan to keep the UK in a "common rulebook" with the EU for goods and agriculture, has urged her to ditch the policy.

He said the party's annual conference starting on September 30 could prove a decisive moment as May is forced to acknowledge the scale of grassroots opposition to her proposals.

"If we come out of conference with her hoping to get Chequers through on the back of Labour votes, I think the EU negotiators would probably understand that if that were done, the Tory party would suffer the catastrophic split which thus far we have managed to avoid," he told the Press Association.

Home Secretary Sajid Javid said a Canada-style deal has a "lot to commend it", but it would not address the problem of the Irish border.

In a sign the Government remained committed to its plan, he told BBC's Andrew Marr Show: "I think the only deal that we've got on the table, that's the Chequers deal."

The toxic atmosphere between the two wings of the Conservative Party was vividly illustrated in the reaction to Johnson's Mail on Sunday column.

Condemning the proposals aimed at resolving the Northern Irish border issue, Mr Johnson said: "We have opened ourselves to perpetual political blackmail. We have wrapped a suicide vest around the British constitution - and handed the detonator to Michel Barnier.

"We have given him a jemmy with which Brussels can choose - at any time - to crack apart the union between Great Britain and Northern Ireland."

Javid rebuked his former Cabinet colleague, saying "there are much better ways to articulate your differences".

Sir Alan Duncan, Mr Johnson's former deputy at the Foreign Office, said: "This marks one of the most disgusting moments in modern British politics.

"I'm sorry, but this is the political end of Boris Johnson. If it isn't now, I will make sure it is later."

Across the Commons, Labour too faces a split over Brexit strategy, with Jeremy Corbyn under pressure to commit to supporting a second referendum.

The trade union movement is preparing to throw its weight behind a public vote on the final Brexit deal because of fears the UK is going to "crash out" of the EU.

Australian Associated Press