Former Chancellor Philip Hammond is to leave Parliament “with great sadness” after deciding against standing as an independent in his Surrey constituency.
Mr Hammond lost the Conservative whip in September after defying Boris Johnson over a no-deal Brexit.
As a result, he cannot stand as a Tory candidate in Runnymede and Weybridge, which he has represented since 1997.
He said he would not stand as an independent as that would be a “direct challenge” to the party he loved.
Mr Hammond was among 21 Tory MPs thrown out of the parliamentary party in September for backing legislation designed to stop the UK leaving the EU without a deal – the so-called Benn Act.
Unlike a number of the group, he has not had the whip restored after rebelling again earlier this month to back Labour calls for more time to scrutinise Boris Johnson’s deal.
The PM blamed him and other former Tory rebels for stopping the UK leaving the EU on the 31 October deadline.
In a letter to constituents, Mr Hammond said he continued to feel “aggrieved” at his punishment given he had been a member of the party for 45 years and had served as an MP for more than two decades.
But he said he would not follow the lead of a number of former colleagues, such as Dominic Grieve and Anne Milton, who are standing as independents in the 12 December election.
“I remain a Conservative and I cannot therefore embark on a course of action that would represent a direct challenge in a general election to the party I have supported all my adult life.
“I will remain an active party member and will continue to make the case for doing whatever is necessary to deliver a close negotiated future economic and security partnership with the EU.”
Mr Hammond served as chancellor for three years under Theresa May and before that was foreign secretary, defence secretary and transport secretary under David Cameron.
He acquired the nicknames Spreadsheet Phil and Box Office Phil for his attention to detail and somewhat dry political style.