Boris Johnson ruled himself out of running for the Conservative leadership on Sunday, despite claiming to have the necessary support.

“I believe I am well placed to deliver a Conservative victory in 2024 — and tonight I can confirm that I have cleared the very high hurdle of 102 nominations, including a proposer and a seconder, and I could put my nomination in tomorrow,” said the former prime minister.

“There is a very good chance that I will win the election with Conservative Party members — and that I will be back in Downing Street on Friday,” he said.

Johnson added, “But in the course of the last days I have sadly come to the conclusion that this would simply not be the right thing to do. You can’t govern effectively unless you have a united party in parliament.”

Due to the failure to reach an agreement with Rishi Sunak and Penny Mordaunt, Johnson stated, “I am afraid the best thing is that I do not allow my nomination to go forward and commit my support to whoever succeeds.”

A little more than four months after an unprecedented ministerial rebellion ended his scandal-plagued reign and he announced his resignation in a speech outside 10 Downing Street, speculation was rife that Johnson would once again try to win the leadership of his ruling Conservative Party and become the United Kingdom’s new leader by default.

“No politician in postwar political history has ever lost their party’s leadership at the same time as losing the premiership and come back to win both,” Tim Bale, a politics professor at Queen Mary University of London, told NBC News in an email Sunday.

The party was forced to look for a new leader after Johnson’s successor, Liz Truss, resigned on Thursday after a disastrous and quickly reversed economic plan that sent the pound plummeting and her government into chaos. She was only in office for six weeks.

Several lawmakers, including former Cabinet colleagues Ben Wallace, the country’s defense minister, and former Interior Minister Suella Braverman, had called for Johnson’s return.

While former Defense Minister Penny Mourdant announced her candidacy last week, Johnson’s main opponent will most likely be former Finance Minister Rishi Sunak, who announced his candidacy on Sunday.

Both were defeated by Truss in the previous election, but Sunak appears to have secured the support of prominent figures on the party’s right wing this time around.

Among those who backed Sunak was Steve Baker, an influential lawmaker on the party’s right and a former supporter of Johnson’s who is now calling for him to step down.

If found guilty, he could be forced to resign or be suspended from office, which Baker described as a “guaranteed disaster.”

Others have pointed out that Johnson’s three years as prime minister were marred by scandals, and he was eventually forced to resign after more than 50 members of his government resigned, including Sunak.

They resigned following allegations that Johnson failed to disclose information about a lawmaker who was appointed to a senior position despite allegations of sexual misconduct.

Former Conservative Party leader William Hague warned on Friday that Johnson’s return would send the party into a “death spiral.”

Whoever wins must obtain nominations from 100 of the 357 Conservative lawmakers by Monday, implying a field of three.

If two candidates receive that level of support, they will face a vote of the party membership, with the winner being announced on Friday.

To those who support Johnson, including Foreign Minister James Cleverly and former Chancellor Nadhim Zahawi, he is a vote-winner with his celebrity image and brand of energetic optimism. His supporters believe he can secure the required 100 votes in Parliament.

“There is a tendency, not least amongst his supporters, but also in parts of the media, to exaggerate Boris Johnson’s electoral appeal,” says Anand Menon, a professor of politics and foreign affairs at Kings College London.