Exeter MP Ben Bradshaw, who sits on parliament’s transport committee, has been at Westminster for 25 years.
He said: “It is with considerable sadness that I have decided not to stand again at the next general election.
“There is never a perfect time to step down in politics and the exact timing is dictated by the electoral cycle. I will be 62 this year. If I fought the next election and won, I could be pushing 70 by the end of the next parliament.”