Liz Truss will enter Downing Street after her triumph in the Tory leadership contest as she prepares to roll out an emergency support package to deal with the energy crisis.
Following her victory over Rishi Sunak, the new party leader will fly to Balmoral on Tuesday where she will be formally invited by the Queen to form a government.
She will then return to Westminster where she is expected to address the nation for the first time as prime minister before getting down to the business of appointing her ministerial team.
A number of key allies and supporters have already been pencilled in for some of the most senior roles, including Business Secretary Kwasi Kwarteng who is widely expected to be given the crucial role of chancellor.
If confirmed he will have the task of delivering on her promised “bold” plan to deal with surging energy bills which have plunged households and businesses into crisis.
The Daily Telegraph reported that among the measures under consideration was a scheme – costing tens of billions of pounds – to freeze bills until the next general election in 2024.
Details could be set out as early as Thursday as the new administration seeks to reassure worried voters following a summer of political paralysis.
Other key appointments are expected to include Attorney General Suella Braverman, who is tipped for promotion to home secretary, and Education Secretary James Cleverly, who is expected to be the new foreign secretary.
Therese Coffey, the Work and Pensions Secretary who is described as Ms Truss’s closest friend at Westminster, is thought to be in line to become health secretary while Ben Wallace is expected to remain as Defence Secretary.
Other appointments will be closely scrutinised by Tory MPs for signs that she is prepared to bring in ministers who did not necessarily support her in the leadership race.
Ms Truss did not enjoy the support of the majority of MPs during the parliamentary stage of the contest, with former chancellor Mr Sunak coming out on top among fellow Tories.
And her 57% to 43% margin of victory in the final ballot of the party, while comfortable, was still narrower than the last three Tory leadership contests that went to a vote.
Mr Sunak indicated that he did not expect to be offered a new ministerial role – although he insisted he would give Ms Truss his “full support” from the backbenches.
However one of his leading supporters, the senior backbencher Mel Stride, said it was essential the new administration drew MPs from across the party.
“It is very important that what we see is an inclusive government – reaching out to all sides of the party based on talent and ability,” he told Channel 4 News.
Mr Cleverly dismissed suggestions that the new cabinet would represent a move to the right – from where Ms Truss drew much of her support during the leadership race.
“I have heard that accusation at the formation of every government that had a Conservative at the head,” he said.
Nevertheless there is expected to be a significant clear-out of ministers, with Deputy Prime Minister Dominic Raab – who described Ms Truss’s tax plans as an “electoral suicide note” – likely to be among the casualties.
Even before Ms Truss had taken office, Pritel Patel announced that she was standing down as Home Secretary having seen her job heavily linked in the media with Ms Braverman.
A fierce Johnson loyalist, Ms Patel was one of the few Cabinet ministers who did not publicly declare for either candidate during the leadership race.
Culture Secretary Nadine Dorries – another outspoken defender of the outgoing Prime Minister – has also chosen to return to the backbenches, despite being offered the chance to carry on.
She remains loyal to Ms Truss, however, and is expected to be awarded a peerage in Mr Johnson’s resignation honours list.
Nigel Adams, another close ally, also tendered his resignation as Cabinet Office Minister.
The day will begin on Tuesday with a final valedictory speech from Downing Street by Mr Johnson before he heads to Balmoral to formally tender his resignation to the Queen ahead of Ms Truss’s arrival.
He is expected to use his address to urge Tories to rally round his successor.
The weather could result in Ms Truss addressing the nation for the first time as prime minister on Tuesday afternoon inside No 10 rather than outside the Downing Street door, as is tradition.
