Former British prime minister Gordon Brown has confirmed he is standing down as an MP.
In a speech in his constituency in Scotland, he said he would quit parliament at the general election in May.
He told constituents it was time for a "new person, with new ideas" to represent them.
Mr Brown added: "We are not leaving Fife. It is London that I'm leaving and for the avoidance of any doubt, I'm not going back to Westminster, not to the House of Commons after the general election and not to the House of Lords."
Mr Brown was ranked Britain's most unpopular prime minister in half a century before he led the Labour party to its worst electoral defeat in a generation in 2010.
He returned to the spotlight this year with several high-profile speeches during the Scottish independence referendum campaign.
The 63-year-old Scot was credited with saving the union by imploring voters to stay in the UK after a sudden surge in Scottish separatist support.
Gordon Brown has announced that he is to stand down as MP for Kirkcaldy and Cowdenbeath at the UK General Election in May 2015
— Gordon & Sarah Brown (@OfficeGSBrown) December 1, 2014He has represented the constituency of Kirkcaldy and Cowdenbeath in southeast Scotland since 1983, when he shared a parliament office with Tony Blair.
Their relationship dominated British politics as Mr Brown, finance minister for a decade, coveted and eventually got Mr Blair's job as prime minister in 2007.
Since stepping down as Labour leader following the 2010 election defeat, Mr Brown has focused mainly on charity work.
In 2012, he was appointed United Nations Special Envoy for Global Education.
British Prime Minister David Cameron said Mr Brown had given a "huge amount in terms of public service" and that he would "go on contributing to public life" even after he stands down as an MP.
Current Labour leader Ed Miliband also paid tribute to the former prime minister.
He said: "Gordon has been a towering figure in politics, he has been a towering figure for the Labour Party.
"He will have to his credit a lot of the achievements of the Labour Party.
"I know he will continue to play an active part in politics in different ways."
On behalf of the Labour Party I want to thank Gordon Brown for his outstanding 32-year parliamentary career.
— Ed Miliband (@Ed_Miliband) December 1, 2014Meanwhile, Scottish Conservative leader Ruth Davidson MSP said Mr Brown's decision to stand down was the right one.
She said following the success of the Better Together campaign, he leaves Westminster with his head held high.
"I think history will judge Gordon Brown more kindly than the rough and tumble of contemporary politics, particularly his time as chancellor.
"A big beast is leaving the stage," she added.
