Theresa May has admitted the UK Government is “in crisis” as she prepares to write to European Council president Donald Tusk in relation to an extension of the Article 50 withdrawal process.

John Bercow provoked uproar at Westminster on Monday when he ruled that the Government could not bring the Prime Minister’s deal back for a third “meaningful vote” unless there were substantial changes.

May voiced her “absolute determination” that MPs should have another chance to vote on her Brexit deal, despite the bombshell intervention of the Commons Speaker.

May’s spokesman said the Prime Minister had made clear if her deal was voted down in the second “meaningful vote” – as happened last week – they would be “in crisis”.

He said events on Monday suggested “that situation has come to pass”.

The spokesman said that May would now be writing to European Council president Donald Tusk ahead of Thursday’s EU summit in Brussels in relation to an extension of the Article 50 withdrawal process.

• Brexit chaos as Commons speaker John Bercow rules out third vote on Theresa May’s deal

The Prime Minister’s official spokesman said: “What you can see from the Prime Minister and her colleagues is an absolute determination to find a way in which Parliament could vote for the UK to leave the European Union with a deal.

“The Prime Minister has been very clear throughout that she wants that to happen as soon as possible.”

Nevertheless, there was said to concern among some ministers that Brexit appeared to be slipping away.

The Leader of the House Andrea Leadsom is understood to have told the meeting: “This used to be the Cabinet that would deliver Brexit and now from what I’m hearing it’s not.”

In a further blow to May, the government’s talks with the DUP, which has 10 lawmakers in parliament, have reportedly stalled and a breakthrough is unlikely at the moment.

The Prime Minister previously said if the deal was defeated in last week’s vote there would have to be an extended delay to Brexit, with the UK staging elections to the European Parliament in May.

However the spokesman said: “She has said in the House of Commons that she does not want there to be a long delay and that she believes asking the British public to take part in European elections three years after they voted to leave the EU would represent a failure by politicians.”

Downing Street confirmed discussions were continuing with the Democratic Unionist Party – which props up the Government at Westminster – in an effort to build support for the deal after last week’s 149-vote defeat.

Former foreign secretary Boris Johnson – one of the most strident opponents of the Withdrawal Agreement – was also seen entering the Cabinet Office for talks.

The Prime Minister’s spokesman said: “She is speaking with and having meetings with colleagues and a lot of those meetings have been focused on Brexit.”

Earlier, Brexit Secretary Stephen Barclay acknowledged Bercow’s ruling made it “more unlikely” there would be an attempt to stage another vote before May heads to Brussels, as No 10 had hoped.

However, he insisted that May’s agreement remained “the only deal on the table”.

“What we need to do is secure the deal,” he told Sky News.

“This is the only deal on the table. The EU is clear it is the only deal on the table. Business needs the certainty of this deal and it is time that Parliament comes together and gets behind it.”

While Bercow cited previous rulings dating back to the 17th century in his Commons statement, Barclay said he had previously made clear the House should not necessarily be bound by precedent.

“What the Speaker has said in his ruling is there needs to be something that is different. You can have the same motion but where the circumstances have changed,” he said.

“So we need to look at the details of the ruling, we need to consider that in the terms of earlier rulings that don’t particularly align with yesterday’s.

“The fact a number of Members of Parliament have said that they will change their votes points to the fact that there are things that are different.”

With less than two weeks before Britain is still formally due to leave on March 29, there was exasperation among leaders of the remaining EU 27 over the continued deadlock in Westminster.

Arriving for a meeting of EU foreign ministers in Brussels, Germany’s Europe minister Michael Roth said they needed “clear and precise proposals” from the UK regarding any Article 50 extension.

“Dear friends in London, please deliver. The clock is ticking,” he said.

“It’s not just a game. It’s an extremely serious situation.”

Meanwhile, Irish premier Leo Varadkar has held talks in Dublin with Tusk ahead of the Brussels summit.

The Irish government has been adamant it will not accept changes to the Northern Ireland backstop – intended to ensure there is no return of a hard border – which remains the main stumbling block to an agreement for many MPs.