According to one of the close allies of Boris Johnson, at least five UK Cabinet ministers are pushing for him to topple Theresa May as Conservative party leader and Prime Minister, but the foreign secretary denied any plans of a coup.
Pressure has been building up on May to step down after a disastrous election result for the Tories, which saw the ruling party's majority slashed and being forced to cobble together a minority government with the support of Northern Ireland's Democratic Unionist Party (DUP).
"A handful of senior people have pledged their loyalty to Boris at Cabinet level", a Johnson ally told 'The Sunday Times'.
"He has been inundated with messages of support... We need a Brexiteer. Boris is the only option with the liberal values, Brexit credentials and popular appeal", he added.
But Johnson reacted to media speculation on Twitter by dismissing any rebellion: "I am backing Theresa May. Let's get on with the job."
The latest leadership speculation comes a day after two of May's closest advisers, her joint chiefs-of-staff Fiona Hill and Nick Timothy, resigned amid recriminations about their controlling management style.
May had been reportedly given an ultimatum to get rid of the duo or face a leadership challenge by Monday.
"Theresa May is a dead woman walking and the only question is how long she remains on death row", said George Osborne, who had been sacked as UK Chancellor when May took over at 10 Downing Street after David Cameron resigned as PM after the Brexit referendum in June 2016.
The new editor of the 'Evening Standard' newspaper and close ally of Cameron added: "Cameron took years getting back to office, winning in seats like Bath and Brighton and Oxford and I am angry when we go backwards and I am not afraid to say that."
The sense of uncertainty about a May-led minority government was made worse on Saturday night by conflicting messages from Downing Street.
An initial statement suggested a deal had been struck with the Democratic Unionist Party (DUP), but a later version said the talks were continuing.
"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", the final statement said.
Meanwhile, DUP leader Arlene Foster has said that talks were ongoing, indicating it may not be such a smooth process after all.
The Opposition Labour leader, Jeremy Corbyn, has also said that his party is waiting in the wings to take charge after he defied pollsters' predictions by gaining 30 seats in Thursday's election, leaving a hung Parliament.
He said that Labour under his leadership was "quite ready and able to put forward a serious programme of government", which he said "obviously has massive support in this country".
"We can't go on with a period of great instability", he said, adding that the Labour Party was ready to fight another election campaign.
A latest YouGov poll for 'The Sunday Times' revealed that voters, by a margin of 48 per cent to 38 per cent, believe the Prime Minister should resign and for the first time Corbyn has drawn level with May on the question of who would be the best Prime Minister.