Story Highlights• Gordon Brown replaces Tony Blair as British prime minister
• Former finance minister promises "new government with new priorities"
• Blair receives standing ovation from lawmakers in final session as prime minister
• Blair expected to be appointed as peace envoy by Mideast Quartet
Adjust font size:
LONDON, England (CNN) -- Gordon Brown is the UK's new prime minister after replacing the outgoing Tony Blair on Wednesday.
"This will be a new government with new priorities, meeting the concerns and aspirations of the whole country. Let the work of change begin," said Brown as he arrived at 10 Downing Street following an audience with Queen Elizabeth II in which he was asked to form a new government.
Hours after stepping down, Blair was appointed to serve as a special envoy to the Middle East by the Mideast Quartet. (Full story)
In a joint written statement, the United States, Russia, the European Union and the United Nations confirmed the appointment. (Watch how Arabs responded to Blair's appointment )
Earlier, Blair addressed lawmakers in the House of Commons for the final time after more than a decade in power.
He was then photographed with his family outside No. 10 before leaving for Buckingham Palace to tender his resignation to the queen.
"I wish everyone, friend or foe, well and that is that, the end," he said in a fulsome and emotional tribute to his parliamentary colleagues following a good-humored session of Prime Minister's Questions.
Blair, who is set to become an envoy for Mideast peace, received a standing ovation as he stepped down from the dispatch box.
Opposition Conservative leader David Cameron led praise for his outgoing rival, hailing his "remarkable achievement" in serving as prime minister for 10 years and highlighting his commitment to the Northern Ireland peace process and to world development. (Watch as CNN's Christiane Amanpour reflects on Blair's legacy )
"For all of the heated battles across this dispatch box, for 13 years he has led his party, for 10 years he has led our country, and no one can be in any doubt in terms of the huge efforts he has made in terms of public service," said Cameron.
Democratic Unionist Party leader Ian Paisley, Northern Ireland's first minister and a key player in the peace process, said Blair had always treated him with "the greatest of courtesy" -- and wished Blair luck in his anticipated new role representing the Mideast Quartet. (Full story)
"I just want to say to the prime minister this one word: He has entered into another colossal task," said Paisley.
"I hope that what happened in Northern Ireland will be repeated and at the end of the day he will be able to look back and say it was well worthwhile."
Blair stands down after a decade in which Labour won a party-record three straight general elections, in which lasting peace was brought to Northern Ireland and the British economy enjoyed a record sustained boom.
But the Iraq war, the cash-for-honors row and his government's perceived preoccupation with media spin damaged Blair's reputation.
With anti-war protesters gathered outside Downing Street on Wednesday, Blair was once again forced to address the issue of Iraq as he paid tribute in parliament to UK soldiers killed in action during the past week.
"I am truly sorry about the dangers that they face today in Iraq and Afghanistan," Blair said.
"I know some may think that they face these dangers in vain; I don't and I never will. I believe they are fighting for the security of this country and the wider world against people who would destroy our way of life.
"Whatever view people take of my decisions, I think there is only one view to take of them: they are the bravest and the best."
One protester, Donna Mahoney, whose husband, Peter, committed suicide after serving in Iraq, said she was ecstatic that Blair was quitting.
"I needed to see him leave to prove that he is gone now and to close another part of this chapter," she told the UK's Press Association. "But I can't believe that he is going to be a peace ambassador."
Change of style
Prior to his re-election in 2005, Blair had vowed to serve a full third term. But political infighting within Labour ranks culminated in a political coup last year that saw him pledge to leave office early, honoring a long-standing pact to make way for Brown.
CNN's European Political Editor Robin Oakley said Brown would introduce a different style of government, restoring a more serious tone to British politics after the "sofa-style" decision-making of the Blair years.
"He is a very serious, committed politician very much driven by the values that he learnt from his Presbyterian minister father. We're going to see a lot less glitz and glamour," said Oakley.
"It will be very much a more 'get on the with the job' style of government," said Oakley. "There will be a lot of serious purpose."
"People are hopeful there is going to be a change of mood and a change of pace very quickly," Labour lawmaker Jeremy Corbyn, an outspoken critic of Blair and the Iraq war, told Reuters.
"The first priority of Gordon Brown has to be recognizing the disaster of the strategy in Iraq and making plans for the withdrawal of our forces."
Brown is expected to introduce a more serious style of politics.