Aberdeen North MP Frank Doran has announced that he is to stand down at the next General Election.
The Labour politician has served at Westminster for a total of 23 years.
He said it had been an enormous privilege to represent the city in the House of Commons but it was now time to stand aside.
The announcement was made at a meeting of members of the Labour Party in Aberdeen.
Mr Doran said: "By the next election I will have been an MP for 23 years, I think it is time to step aside to give someone else the chance from the Labour Party the opportunity to represent Aberdeen in Westminster.
"It has been an enormous privilege to represent the City in Parliament and I am grateful for the support which has been given to me by my own party members and citizens of Aberdeen in that time."
He said he would work to elect a Labour Government in 2015 and ensure Aberdeen North continues to send a Labour MP to Westminster.
Mr Doran was first elected to Westminster in 1987 and served as shadow energy minister under Neil Kinnock between 1988 and 1992.
That year, however, he became the only sitting Labour MP to lose his seat to the Conservatives although he was returned to parliament again in 1997.
He has been a staunch campaigner for improved safety in the North Sea and runs the All Party Parliamentary Fisheries Group and the All Party Parliamentary Dance Group, lobbying for both industries. Mr Doran is on the Commission of the House of Commons and is chairman of the Commons Arts Committee.
He is married to Labour MP for Lewisham Deptford Dame Joan Ruddock, who has also announced that she will be standing down at the next General Election, due to be held in 2015.