Theresa May suffered another Brexit defeat as MPs voted to rule out a no deal Brexit.

Tory MPs defied the party whips and backed an amendment to rule out no deal under any circumstances.

MPs are now expected to vote on Thursday to approve asking the EU for an extension to the Brexit date.

On Tuesday MPs overwhelmingly rejected the Prime Minister’s deal.

Tonight they voted to rule out no deal under any circumstances.

With just 16 days until Brexit day on March 29, the House of Commons will decide whether to tell the Prime Minister to go back to Brussels and ask the EU to agree to extending the leave date.

It leaves the country with no idea when, or indeed if, the UK will definitely leave the EU after Theresa May once again raised the prospect of a second referendum, which she warned would damage trust in MPs.

The SNP said the United Kingdom is now in the grip of a “constitutional crisis”.

The House of Commons voted by a narrow majority of just four for the amendment.

The Conservative leadership had instructed its MPs to vote against the plan, which was tougher on no deal that its own motion, but it was passed by 312 to 308.

The final, amended vote was passed with an even bigger majority of 321 to 278

The vote is not legally binding but puts pressure on Theresa May to take heed of it and ensure the UK doesn’t leave until an acceptable deal is agreed.

Following the vote the Prime Minister suggested she could bring back her deal.

She reminded MPs the “legal default” is the UK leaves the EU on March 29 “without a deal unless something else is agreed.”

“The onus now is on us to find out what that is.”

She added: “We could leave with the deal negotiated but subject to a second referendum.”

However she said that would “damage the fragile trust between the British Public and the members of this House.

“We could seek to negotiate a different deal but the EU has said the deal is the only one on the table.“

Labour said it would seek to propose an alternative cross party compromise Brexit deal.

Ian Blackford, SNP Westminster leader said: “We are in a constitutional crisis at the making of a Prime Minister that has run down the Brexit clock.

“I am delighted this house has said it wants to rule out no deal. She has failed.”