Theresa May will carry out a reshuffle of her cabinet and junior ministers this week, Downing Street has confirmed. The jobs of the education secretary, Justine Greening, and the party chairman, Sir Patrick McLoughlin, are particularly vulnerable, it is believed.

Greening was no enthusiast for the prime minister’s push to expand the number of grammar schools and it is widely reported that the Conservatives are anxious to refresh their education policies. However, in an indication that she could resist any attempt to move her, the education secretary posted a series of messages on Twitter heralding her achievements in the role and twice declared: “School standards are rising.”

Downing Street refused to comment on possible changes on Saturday evening but it is understood that the foreign secretary, Boris Johnson, the chancellor, Philip Hammond, the Brexit secretary, David Davis, and the home secretary, Amber Rudd, would all be continuing in their posts.

Speculation about the fate of the business secretary, Greg Clark, and Andrea Leadsom, the leader of the House of Commons, has suggested they may also face moves.

It is known that the prime minister was looking to replace her close friend and ally Damian Green at the Cabinet Office after he was forced to quit in December. Green was told to step down as first secretary of state after he admitted lying about the discovery of pornographic images on his Commons computer during a police raid. He was the third minister to be forced from office following resignations by the defence secretary, Sir Michael Fallon, and the international development secretary, Priti Patel.

On Saturday night, May was said to be preparing to appoint the health secretary, Jeremy Hunt, to replace Green although it was also reported that the announcement may be delayed while the NHS winter crisis continues. Boris Johnson, who some said a week ago could be moved, is now thought to be safe in his role, at least for the time being.

More sweeping changes in junior ministerial ranks on Tuesday are planned by the prime minister, it was claimed. May was said to be putting the finishing touches to a series of promotions for younger MPs to roles in government. Several commentators said the Conservative party was anxious to revive its fortunes with the help of fresh faces and a more varied cast of ministers and aides. More women and younger MPs are expected to be promoted and given roles at junior ministerial levels.

The Sunday Telegraph suggested that promotions were also expected for other figures including Dominic Raab, the justice minister. Raab, a leading Brexiter, would replace Brandon Lewis as the immigration minister, the report said. Raab would then join the cabinet and take responsibility for steering the immigration bill through parliament. It was also suggested that May would use the opportunity to introduce greater diversity into ministerial ranks, with the black former army officer James Cleverly tipped for a senior party role.

Among MPs from the 2015 intake who could win promotion are government aides such as Suella Fernandes, the head of the party’s European Research Group, and Seema Kennedy, the PM’s parliamentary private secretary.