In the biggest move, the Prime Minister is expected to announce a new Secretary of State, effectively her deputy, after Damian Green was forced to resign from the post last month.

Jeremy Hunt, currently the Health Secretary, is tipped to take over the Cabinet Office, although the current crisis in the NHS could mean he stays in the department for the time being.

Theresa May’s changes are not expected to affect foreign, finance, interior and the Brexit ministers, The Sunday Times has claimed.

Mrs May is expected to use the reshuffle to promote a series of younger MPs from diverse backgrounds.

Mrs May is also understood to be preparing to promote a number of MPs from the 2015 intake, after accepting that the Government is in need of fresh faces, as well as a more diverse cast of ministers and aides.

The drive could see younger MPs rewarded with government aide posts after a difficult six months for Mrs May, as well as possible promotions for existing aides.

However Justine Greening is fighting for her job as Eduction Secretary, The Telegraph has revealed, as the Government attempts to reinvigorate its approach to education.

Ms Greening’s successor will be tasked with leading a major push to convince voters that the Conservatives are the party of education ahead of the local elections in May.

But Ms Greening appears to be unwilling to go without a fight.

The Eduction Secretary posted a series of messages on Twitter heralding her achievements in the role and twice declaring: “School standards are rising.”

Ms Greening’s posts signal how the reshuffle will test Mrs May’s apparently renewed strength as Tory leader after securing a “first round” agreement in Brexit negotiations with the European Union, and putting a series of damaging Cabinet scandals behind her.

Ms Greening, like other ministers facing a downward move, could resist a demotion or threaten to cause problems for the Prime Minister on the back benches.

Other ministers tipped to be demoted include Greg Clark, the Business Secretary, Sir Patrick McLoughlin, the party chairman, and Andrea Leadsom, the Leader of the Commons.

The rise of MPs from the 2015 intake could see promotions for government aides such as Suella Fernandes, the head of the party’s European Research Group, and Seema Kennedy, the Prime Minister’s parliamentary private secretary, as well as possible rewards for displays of loyalty such as the decision by Vicky Ford, the former MEP, to support the Government in a crucial vote last month over its Withdrawal Bill, despite earlier misgivings.

Mrs May, who became Prime Minister shortly after the Brexit vote in mid-2016, has been widely expected to rejig her ministerial team after a damaging 2017 when she called a snap election only to lose her parliamentary majority.

May's Conservative Party is running neck and neck with the left-wing Labour Party in opinion polls and has been split by differences about what kind of relationship Britain should seek with the European Union after it leaves the bloc in 2019.

The foreign, finance, interior and Brexit ministries are run by Boris Johnson, Philip Hammond, Amber Rudd and David Davis.