Boris Johnson has secured the support of several Conservative MPs who previously called for him to resign in the summer.
Though the former prime minister has yet to declare he will run in the race to replace Liz Truss, he has the public support of several cabinet ministers and more than 40 MPs.
Some of those MPs appear to have changed their mind on Mr Johnson since his resignation.
Priti Patel, the former home secretary, has said she will back him, but in July Ms Patel told Mr Johnson he had lost the support of the Tory party and should not go on.
Chris Heaton-Harris, the Northern Ireland secretary, who has tweeted his support for Mr Johnson, is also reported to have been present at the meeting.
Simon Clarke, the levelling up secretary, also declared he wants Mr Johnson to replace Ms Truss, despite previously saying his resignation as prime minister was the “right decision”.
Mr Johnson returned to the UK on Saturday morning from the Dominican Republic, where he was said to be “taking soundings” about a potential return to No 10 after Ms Truss’s dramatic resignation on Thursday.
His allies have said he is “up for it” but he is likely to be opposed by his former chancellor Rishi Sunak, whose resignation was key in forcing Mr Johnson’s departure from Downing Street in the summer.
Penny Mordaunt, the leader of the Commons, formally announced her bid on Friday afternoon.
Amanda Milling, MP for Cannock Chase, also tweeted her support for Mr Johnson, saying he has a “proven track record of delivery for the British people”. But when he resigned Ms Milling said it was the right move “as the damage to our party and country was getting too much”.
Similarly, Shaun Bailey, MP for West Bromwich West, tweeted it was “time to #BringBackBoris”, but had said he could no longer support him when he was prime minister and called for “fresh leadership”.
Anthony Higginbotham has also come out for Mr Johnson, but had previously urged him to resign, saying: “Loyalty matters. But as the Member of Parliament for Burnley my first loyalty is, and always will be, to the public. It’s for that reason that I can no longer in good conscience continue supporting the current leader of my party.”
John Whittingdale, MP for Maldon, who has indicated he would back Mr Johnson, previously said there was “absolutely no alternative” to him resigning as prime minister and said it was clear he “simply couldn’t continue”.
Jonathan Gullis, who resigned his role as parliamentary private secretary to the Northern Ireland secretary, has also indicated he will support Mr Johnson. The MP for Stoke-on-Trent North reportedly said he had lots of people from across his constituency telling him to “bring back Boris”.
Karl McCartney, the MP for Lincoln, backed Mr Johnson’s return but before his resignation said: “It has become clear to the prime minister, Boris Johnson MP, that he no longer has the confidence of a growing number of his colleagues in the Conservative Parliamentary Party.
“Therefore, the time has come for the prime minister to take the decision to resign and allow the Conservative Party the opportunity to select and elect a new leader.”
On Monday Tory MPs will vote on which two candidates should be put forward to the party membership. Candidates have until 2pm to secure 100 nominations.
The membership will then vote on who should become leader of the party and the prime minister, with the result announced on Friday.