Johnson not running for UK prime minister, setting up ex-Chancellor Rishi Sunak for the post

Former Prime Minister Boris Johnson on Sunday announced that he will not run for leadership of the Tory Party, setting up former Chancellor Rishi Sunak to be the next U.K. prime minister following Liz Truss' resignation last week. 

Johnson, who had not formally announced his candidacy, had the support of 102 members of parliament, 57 of whom were public about their support, the BBC reported. Candidates are required to have the support of 100 MPs to run for party leader and secure the position of prime minister.

Sunak has the support of 147 MPs and is the front-runner in the race to be the next prime minister. The only other candidate who has declared intentions to run for party head is Penny Mordaunt, who has the support of 24 MPs. The British press reports that 227 out of 357 Tory MPs have publicly stated who they are backing.

Candidates have until 2 p.m. local time on Monday to garner enough support. If there is more than one candidate, then the party will vote for the next prime minister later in the day.

Johnson, who resigned in July, said he believes that he would best serve the U.K. by working to avoid a general election.

"A general election would be a further disastrous distraction just when the Government must focus on the economic pressures faced by families across the country," he said. 

Johnson acknowledged "there is a very good chance" he has the support to become prime minister again, but said, "I have sadly come to the conclusion that this would simply not be the right thing to do."