A cross-party group of MPs is to launch a fresh attempt to prevent a no-deal Brexit if Theresa May cannot reach an agreement with Brussels by mid-March.

The group, including Labour MP Yvette Cooper and Tory former minister Sir Oliver Letwin, have said they are ready to table an amendment enabling Parliament to force ministers to seek a delay if there is no deal in place.

The move comes as it was reported the Prime Minister’s chief EU adviser Olly Robbins has suggested MPs could be faced with a choice between accepting her deal or seeing Britain’s withdrawal put on hold for an extended period.

BrexitOlly Robbins is said to have warned of a long delay unless MPs back Theresa May’s deal (PA)

ITV news reported that Mr Robbins was overheard in a Brussels hotel bar on Monday telling colleagues the EU would probably give the Government an extension to the Article 50 withdrawal process.

He was said to have indicated that if MPs did not vote for a deal, then the delay would be “a long one”.

“The issue is whether Brussels is clear on the terms of extension. In the end they will probably just give us an extension,” he was quoted as saying.

“Got to make them believe that the week beginning end of March… Extension is possible but if they don’t vote for the deal then the extension is a long one…”

The comments by Mr Robbins – a key figure in the negotiations with the EU – will fuel the suspicion among MPs that Mrs May is trying to “run down the clock” to Brexit day on March 29 in an attempt to force them to back her agreement.

Publicly the Prime Minister has always insisted the UK will leave on time – although a number of Cabinet ministers have raised the possibility of an extension.

A Government spokesman said: “We would not comment on alleged remarks from a private conversation which is said to have been overheard in a hotel bar.”

Meanwhile, the group led by Ms Cooper and Sir Oliver said they were preparing plans to enable Parliament to prevent the country falling into a no-deal Brexit “by accident”.

The move follows the announcement by Mrs May on Tuesday that she will make a further Commons statement on February 26 and table an amendable motion to be debated and voted on by MPs the following day, if she has not got a deal at that point.

The group say they would then put down an amendment creating parliamentary time for a bill requiring the Prime Minister and Parliament to decide by mid-March whether the UK is leaving with a deal, without a deal or whether it will seek an extension to Article 50.

BrexitSir Oliver Letwin is backing move to prevent an ‘accidental’ no-deal Brexit (Dominic Lipinski/PA)

Ms Cooper said: “This bill creates a Parliamentary safeguard to prevent us drifting into no-deal by accident, and to prevent those crucial decisions being left until the final fortnight.”

A similar amendment by Ms Cooper and the Tory former minister Nick Boles was defeated in the Commons last month.

However supporters of the plan believe that as the calendar counts down towards March 29, it will focus the minds of MPs on all sides who believe no-deal would be a disaster for the UK economy.

Sir Oliver added: “Any MP who genuinely wants to prevent an under-prepared no-deal Brexit will need to vote for this bill at the end of February.

“It is the only way of giving the House of Commons the time to produce a consensus about a positive way forward if the PM cannot get her deal through by mid-March.”

Other MPs supporting the move include the senior Labour MP Hilary Benn, Tory former attorney general Dominic Grieve and the Liberal Democrat Norman Lamb.

It is also backed by Tory MP Dame Caroline Spelman and Labour’s Jack Dromey, who last month tabled a non-binding amendment opposing a no-Brexit which did win Commons support.

Earlier, Mrs May set out plans to short circuit parliamentary rules in order to get a Brexit deal ratified in time for the UK to leave the EU on March 29.

The Prime Minister told MPs that she would enable the House of Commons to lift a requirement for a 21-day delay before any vote to approve an international treaty.

But Labour pledged to oppose the move, accusing the Government of showing “contempt for our democracy”.

In a Commons statement, Mrs May acknowledged she would need “some time” to seek legally-binding changes from the EU to the controversial backstop for the Irish border.

With 45 days to go however, Mr Grieve warned time was running perilously short under the terms of the Constitutional Reform and Governance Act which requires 21 sitting days before the ratification of any international treaty.

Downing Street insisted by the time the 21-day period to consider the Brexit treaty kicked in, MPs would already have passed judgment on it in the “meaningful vote” and the Withdrawal Agreement Bill.

Mrs May sidestepped demands from several MPs to spell out whether she would ask the EU for an Article 50 extension if she hit the March 29 deadline with no agreement.

In stormy exchanges in the Commons, the SNP’s Westminster leader Ian Blackford risked being thrown out of the chamber after shouting “liar” at the Prime Minister.

Labour leader Jeremy Corbyn suggested she was “running down the clock” on Brexit in the hope that MPs will be “blackmailed” by the fear of a no-deal scenario into supporting a “deeply flawed” agreement.

“She is playing for time and playing with people’s jobs, our economic security and the future of our industry,” he said.

Mrs May told the Commons: “We now all need to hold our nerve to get the changes this House requires and deliver Brexit on time.”