The MP for North East Bedfordshire, Alistair Burt, has announced his decision to stand down at the next election.
Alistair Burt was one of 21 Tory rebels stripped of the Conservative whip after backing plans to block a no-deal Brexit.
Explaining his decision not to stand again in a letter to party members in North East Bedfordshire, Mr Burt said: "It has become clear that I have a fundamental and unresolvable disagreement with our party leadership on the manner in which we leave the EU, and the consequences going forward of doing so.
"This is very likely to be at the root of the next election, and I believe it is unfair of me to present you with a conflict of interest between my views and those of the party at an election, even if current circumstances do not result in my having the whip in Parliament removed."
Mr Burt, who was MP for Bury North from 1983 to 1997 before winning North East Bedfordshire in 2001, is well regarded in Westminster as a moderate voice and he raised concerns about a shift to the extremes in politics.