Remain-supporting MP Dominic Grieve may face deselection after suffering a vote of no confidence by his local Conservative association.
Members of Beaconsfield conservative association voted by 182 to 131 against the former Attorney General, although the vote has no standing under party rules.
Mr Grieve has been one of the most prominent remain-supporting Conservative MPs, and addressed the People’s Vote rally in Westminster last weekend.
Association chairman Jackson Ng said: "Our members had a robust discussion with our MP, Dominic Grieve QC on Brexit before voting on a motion of confidence in him as our MP, which, I can confirm with a heavy heart that he failed to retain.
"He remains our Conservative MP but I will be speaking as soon as possible to my fellow officers and the executive council."
The opposition in the constituency to Mr Grieve is reported to have been organised by the former Ukip candidate who stood against him in the 2017 general election, Jon Conway.
Former Tory MP Anna Soubry, who was also at the forefront of the Remain wing of the Conservative Party until she defected to join the Independent Group, branded the vote "disgraceful".
She tweeted: "More evidence that the uncompromising dogmatic right is running the @Conservatives #DominicGrieve is one of the finest, most courageous Parliamentarians ever - who has always put his country first & championed all his constituents."
Mr Grieve had previously told MPs he had “never felt more ashamed” of his party over its handling by Brexit.
However he denied that he planned to follow Ms Soubry in quitting the party, telling talkRADIO he was a “Conservative to my fingertips.”