THERESA May is a “dead woman walking,” George Osborne, the former Chancellor, has insisted as initial talks involving the Democratic Unionist Party to prop up the minority Conservative Government are said to have made good progress.

And it became clear Cabinet members have staged something of a coup following the election result by demanding the Prime Minister approaches government in a more collective and collegiate way rather than relying on a small inner circle of advisors.

Mr Osborne, who was sacked as Chancellor by Mrs May last year and who now edits the London Evening Standard, said the only question now hanging over her was how long she was “going to remain on death row".

Dominic Rabb, the former minister, hit out at Mr Osborne, saying most MPs would see his jibe as “disloyal, unprofessional and frankly pretty self-indulgent”.

However, Anna Soubry, the former business minister and a staunch Remainer, suggested her party leader was “set to go in due course,” which, she agreed, would be by the end of the year.

Arlene Foster, the DUP leader, is set to hold talks with Mrs May in Downing Street on Tuesday to finalise what would be a so-called confidence and supply deal ie the Northern Irish party would support the Conservatives in key votes at Westminster such as on the Queen’s Speech and the Budget.

However, there was confusion over the weekend when No 10 suggested a deal had been done after talks in Belfast but the DUP made clear this was not the case and discussions would continue into the coming week.

Mrs Foster told Sky News: "We had very good discussions yesterday with the Conservative Party in relation to how we could support them in forming a national government; one that would bring stability to the nation. Those discussions continue."

The 10 DUP MPs could prove crucial in supporting the Conservatives on key votes after Thursday's election saw Mrs May lose control of the Commons.

However, potentially more important are the views of Ruth Davidson’s Scottish Conservatives, who number 13. It seems clear that the Tory contingent from north of the border will form its own distinct group led by David Mundell, the Scottish Secretary.

Already, Ms Davidson has called for an “open Brexit” in which jobs and economic growth are put ahead of controlling immigration and has raised concerns about the social policies of the DUP particularly on areas of LGBT rights.

The strength of any Con-DUP deal looks set to be tested when the Commons meets with an upbeat Jeremy Corbyn vowing to try to bring down the Tory Government by defeating Mrs May in Parliament and insisting: "I can still be Prime Minister."

But Chris Grayling, the Transport Secretary, said that while his party had had a "disappointing" election, he stressed that it was "not exactly a rosy story" for Labour either.

He told ITV’s Peston on Sunday that, despite their major gains in Thursday's election, Labour was no further forward than in 2010, when Gordon Brown lost.

He added: "I suspect that a number of people voted for Jeremy Corbyn because they didn't think he would become Prime Minister."

In another sign of the dangers facing Mrs May, it was reported that Boris Johnson was either being encouraged to make a leadership bid in an effort to oust her or was preparing one; a claim dismissed as "tripe" by the Foreign Secretary.

The talks were in line with Mrs Foster's "commitment to explore how we might bring stability to the nation at this time of great challenge", her party said in a statement.

It continued: "The talks so far have been positive. Discussions will continue next week to work on the details and to reach agreement on arrangements for the new Parliament."

Sir Michael Fallon, the Defence Secretary, made clear any deal with the DUP would only apply to "big issues" like the economy and security.

Speaking on the BBC’s Marr Show, the Scot distanced himself from the DUP's conservative stance on social issues, saying: "It doesn't mean we now agree with all their views."

He also made clear that, leading a minority government, Mrs May would take a different approach to government.

Referring to the resignations of former chiefs of staff Fiona Hill and Nick Timothy, Sir Michael said: “You have already seen some changes of personnel in Downing Street. I welcome that of course. We are going to see, I hope, more collective decision-making in the Cabinet. I and other senior colleagues have made that clear to her.

"You will also see that she will want to work much more closely with the parliamentary party both in the conduct of business and the development of policy," he added.

Earlier, No10 had said: "We can confirm that the Democratic Unionist Party have agreed to the principles of an outline agreement to support the Conservative Government on a confidence and supply basis when Parliament returns next week."

Following talks between Mrs May and the DUP on Saturday night, a second statement confirmed that no final deal had actually been reached.

A Downing Street spokeswoman said: "The Prime Minister has tonight spoken with the DUP to discuss finalising a confidence and supply deal when Parliament returns next week.

"We will welcome any such deal being agreed, as it will provide the stability and certainty the whole country requires as we embark on Brexit and beyond.

"As and when details are finalised both parties will put them forward."

Mrs May needs support in Parliament because the Queen's Speech setting out the Government's programme is due on June 19 with a crucial vote on it expected after a few days' debate.