The former Chancellor, Philip Hammond, has announced he is standing down as an MP after being thrown out of the Conservative Party for disobeying Prime Minister Boris Johnson over Brexit.
Hammond, who rose to prominence under David Cameron and then became Chancellor under Theresa May, had been out of favour since Johnson took over in Downing Street in July.
Hammond wrote in a letter to his constituents in affluent Surrey, just outside London: "I am saddened to find myself in this position after 45 years of Conservative Party membership.”
Hammond, 63, was one of 21 Tory MPs who had the party whip removed in September after they voted for the Benn Act, which stopped the UK leaving the EU without a deal.
Ten of the 21 were allowed back into the party last month but Hammond was not and, unlike Dominic Grieve, he has decided against standing as an independent in the 12 December general election.
Hammond had a majority of 18,000 at the 2017 election and his safe seat is expected to be given to a young Johnson loyalist.
In his letter Hammond wrote: "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."