Labour backbencher Don Touhig today became the latest MP to announce that he will be standing down at the general election.
The former minister was first elected for the safe Labour seat of Islwyn in South Wales in a by-election in 1995.
He worked for two years as parliamentary private secretary to Gordon Brown when he was chancellor before joining the Government whips' office in 1999.
He went on the hold ministerial posts in the Welsh Office and the Ministry of Defence.
Mr Brown paid tribute to his record, saying: "Don served as a hard-working minister and a distinguished representative within senior parliamentary committees, and yet never lost sight of what mattered to the Islwyn constituents he represented, dedicating himself to a wide range of community groups in South Wales."