Prime Minister Tony Blair urged his party in an emotional farewell speech on Tuesday to put aside squabbles over who succeeds him and focus on winning Britain's next election.
Blair defended the centrist policies he has followed in nine years in power but said the party had to face up to global challenges such as climate change and terrorism as he gave his last address as leader to the Labour Party's annual conference.
He called for a healing of divisions that rocked the party this month when a rebellion by Labour legislators forced him to pledge to step down within a year.
"The truth is you can't go on forever. That's why it's right that this is my last conference as leader," Blair said.
"I will try to help build a unified party with a strong platform for the only legacy that has ever mattered to me -- a fourth term election victory that allows us to keep on changing Britain for the better," he said.
Blair, U.S. President George W. Bush's closest ally in the Iraq war, has been Labour's most successful leader, winning three general elections in a row. The next is expected in 2009.
However, his popularity in the country has waned over his commitment to the U.S.-led Iraq invasion, his policies in the Middle East and his pro-market reforms.
Blair praised finance minister Gordon Brown, his expected successor with whom he has a troubled relationship, but stopped short of endorsing him as future leader.
Brown gave a confident speech on Monday which won over some activists concerned by his poor opinion poll showings against the resurgent Conservatives under new leader David Cameron. He may still face a serious challenge for the leadership.
Blair was rewarded with a rousing send-off as the party rank-and-file put aside their past criticisms to give him a seven-minute standing ovation.
He urged members to adopt an updated form of his reformist "New Labour" philosophy and focus on retaining power, saying he had hated the party's days in the political wilderness.
Labour hoped the Manchester rally would draw a line under infighting over the succession but a reported slur by Blair's wife Cherie against Brown threatened a fragile truce on Monday. A news agency report said she had accused Brown of lying when praising Blair on Monday, although she denied saying it.
Blair drew roars of laughter from the packed conference hall by joking that at least he would never have to worry about his wife running off with the man who lives next door.
Brown lives next to the Blairs in Downing Street in London.
Labour member of parliament Angela Eagle praised Blair's speech. "It was just what the party needed. We will miss him but we also know that in politics times change and things move on."
But John McDonnell, a left-winger who has said he will challenge Brown for the leadership, said Labour needed a radical change of direction to revive its fortunes.
"The Blair legacy is a party trailing in the polls, out of touch with its supporters and having suffered a crushing defeat in the local elections," he said.
The opposition Conservatives said it was time for Blair to go. "Tony Blair's theatrics can't disguise the bitter divisions of this paralysed government which is failing to give the British people the leadership they deserve," party chairman Francis Maude said in a statement.
(additional reporting by Mark Thompson, Sumeet Desai and David Clarke)