Although senior Tory figures, including Lord Ashcroft, reportedly advised the Prime Minister to radically reboot her Cabinet, “big beasts” Chancellor Philip Hammond, Home Secretary Amber Rudd, Foreign Secretary Boris Johnson and Brexit Secretary David Davis are expected to remain in place as the Prime Minister wants to avoid “destabilising the Government”. 

This is despite calls from Brexiteer backbenchers for her to sack arch Remainer Mr Hammond following a war of words in recent months between Number 10 and Number 11.

One senior Tory figure said Mrs May was missing an opportunity not to demote Mr Hammond, seen as one of the most divisive figures on the front bench. 

The source said: “Many people in the party can’t understand how Philip has survived for so long when he is so unpopular and off message. Theresa has been told by a number of people, including Lord Ashcroft, that she should sack him, along with half the Cabinet. 

“What we have currently is a ‘Second XI’ when what’s really needed is a rebirth of the Conservative Party from the top down.” 

“Modernity” is thought to be the theme of the reshuffle, which will take place tomorrow and Tuesday, when MPs from the 2015 and 2017 intake are expected to be promoted to junior ministerial roles. 

Mrs May is understood to be keen to embrace more women and people from black and ethnic minority backgrounds to promote greater diversity throughout the Government.

Kemi Badenoch, 38, who introduced Mrs May’s cough-plagued speech at last year’s Conservative Party Conference, is thought to be among those being lined up for a promotion within the party ranks. 

Health Secretary Jeremy Hunt is widely tipped to become Mrs May’s new de facto deputy following the resignation of Damian Green last month.

Immigration minister Brandon Lewis is tipped to replace Sir Patrick McLoughlin as party chairman, although former Conservative leader Iain Duncan Smith has told colleagues he would gladly accept the job.

Former Territorial Army officer James Cleverly, who gave a moving speech in Parliament last year following the murder of his close friend PC Keith Palmer in the Westminster terror attack, is being touted as deputy chairman. 

The role has gained greater significance following the revelation that party membership is down to 70,000, compared to one million when Margaret Thatcher was in power.

Meanwhile, a massive flurry of bets has been placed on Andrea Leadsom launching a leadership bid, despite rumours she is facing the chop as Leader of the House.

Mrs Leadsom, who ran against Mrs May following David Cameron’s resignation in June 2016 but later withdrew, has seen her odds slashed from 80/1 to 16/1. 

Betway’s Alan Alger said: “The money we’ve seen come in over the last 24 hours could indicate Andrea Leadsom is preparing a bid for the Tory leadership.”

Sources close to the mother-of-three have previously rubbished claims of a challenge. 

Michael Gove, who has been winning plaudits as Environment Secretary, is currently joint favourite to succeed Mrs May at odds of 9/2, along with Mr Johnson. 

According to one senior Tory: “Michael’s on a one-man mission.” 

Mr Gove had been tipped to replace Mr Hammond as Chancellor but a party insider commented: “Michael is extremely bright, but maths is not his strong suit.”