MP John Smith is the grandson of a Labour founder in Wales
A veteran Labour politician has announced he will stand down at the next general election.
Vale of Glamorgan MP John Smith, who is 58, said he had "recently experienced" health problems and wanted time to catch up with family.
He was first elected in 1989 in his constituency and has become known for his campaigning work highlighting the dangers of deep vein thrombosis (DVT).
His constituency chairman said the MP has been "a great champion".
In a statement Mr Smith said: "I will be 60 in the first year of the next parliament and I have recently experienced health problems.
"I have been in politics for nearly 40 years and the greatest honour has been to represent at Westminster the area where I was born and brought up.
"It does not get better than that and I sincerely thank the people of the Vale of Glamorgan for repeatedly returning me to parliament."
As well as his work on DVT, the MP has also been heavily involved in a bid to bring a £12bn Defence Technical College to St Athan in his constituency.
His credentials within the party were well established as he was the grandson of a founder member of Labour in Wales.
The MP said: "I will step down at the next election. Until then, I will work hard to deliver the Defence Technical College on target and continue to represent all the people of the Vale to the best of my ability.
"After that, I have decided to catch up on time with my family, focus on my health and look ahead to new challenges."
Paying tribute, Vale of Glamorgan Labour constituency chairman Stuart Egan said: "We are saddened by this news but fully respect and understand John's decision.
"Since he was first elected as our MP 20 years ago, John has been a great champion of the Vale of Glamorgan.
"Representing the area where he was born and brought up in parliament has never been a 'job' but a labour of love for him."
Jane Hutt, Vale of Glamorgan AM, said Mr Smith has made "an outstanding contribution as an MP by his championing of causes such as the DVT Long Haul flights campaign, resulting in worldwide change, for which he has been rightly honoured".
"I have valued and will miss his friendship, support and advice as a political colleague and ally over the past 10 years," she said.