Conservative leader David Cameron became Britain's youngest prime minister in almost 200 years Tuesday after Gordon Brown stepped down and ended 13 years of Labour government.

Britain's Queen Elizabeth II greets David Cameron, the leader of the Conservative Party, at Buckingham Palace, London, in an audience to invite him to be the next Prime Minister of the United Kingdom, following last week's General Election, Tuesday May 11, 2010.

Cameron said he aims to form a full coalition government with the third-place Liberal Democrats after his Conservative Party won the most seats but did not get a majority in Britain national election last week.
Conservative Party officials told The Associated Press that Liberal Democrat Leader Nick Clegg would serve as Britain's deputy prime minister.

The two officials, who requested anonymity to discuss the appointments ahead of an official announcement, said Clegg and four other members of his Liberal Democrats would win Cabinet posts.

Ex-Conservative Party leader William Hague will serve as Foreign Secretary, and Conservative lawmaker George Osborne has been appointed as new Treasury chief, according to the Conservatives.

A third Conservative official told the AP that party lawmaker Liam Fox will be defense secretary.

The hawkish Fox takes a tough line on Iran's disputed nuclear program, and is a staunch advocate of Britain's retaining a nuclear deterrent.

Cameron, 43, said it would be "hard and difficult work" to govern as a coalition but added that Britain had serious economic issues to tackle. Cameron visited Buckingham Palace and was asked to form a government by Queen Elizabeth II less than an hour after Brown tendered his resignation to the monarch.

Cameron and Clegg's pact would be the first coalition government since World War II.

Arriving at London's Downing Street hand in hand with his wife Samantha, Cameron said he believed that Britain's "best days lie ahead."

Hundreds of onlookers, many of them booing, crowded the gates of Downing Street to watch on, as Cameron swept into his new home less than 90 minutes after an emotional Brown had made a farewell address.

"We have some deep and pressing problems — a huge deficit, deep social problems, a political system in need of reform," Cameron said. "For those reasons, I aim to form a proper and full coalition between the Conservatives and the Liberal Democrats."

"Nick Clegg and I are both political leaders who want to put aside party differences and work hard for the common good and for the national interest," Cameron said.

President Barack Obama telephoned Cameron, inviting him to the United States in July. The pair discussed Afghanistan, Iran, and the Middle East peace process, according to a statement released by the new prime minister's office. Cameron also fielded a call from German leader Angela Merkel, with whom he talked about the world economy.

Standing outside 10 Downing St. alongside his wife Sarah, Brown spoke in strained tones as he wished Cameron well.

"Only those who have held the office of prime minister can understand the full weight of its responsibilities and its great capacity for good," he said.

Brown said he had "loved the job, not for its prestige, its titles and its ceremony, which I do not love at all."

"No, I loved the job for its potential to make this country I love fairer, more tolerant, more green, more democratic, more prosperous, more just — truly a greater Britain."

After his brief statement, the 59-year-old Brown walked hand-in-hand with his wife and young sons John and Fraser down Downing Street, where a car waited to take him to the palace.

Brown spent about 15 minutes inside the palace and was then driven away — no longer Britain's leader. Minutes later he arrived at Labour Party headquarters, where he was greeted warmly by cheering staffers.

Brown told party staff that his deputy Harriet Harman would become interim Labour leader until a formal leadership takes place to select his permanent successor.

Brown's resignation ended five days of uncertainty after last week's general election left the country with no clear winner. It left Britain with its first so-called hung Parliament since 1974. Britain's Conservatives won the most seats but fell short of a majority, forcing them to bid against the Labour Party for the loyalty of the Lib Dems.

Liberal Democrat Treasury spokesman Vince Cable said the details of a deal were being worked on, but he would be "very surprised" if an agreement was formally announced before Wednesday.

"Nothing has been formally agreed," he said. "There has been a lot of progress.

"The details are currently in the process of being sorted."

Clegg's Liberal Democrats have a more complex process, and may need to hold a meeting of around 200-300 grass roots members to formally ratify the coalition. Their joint government needs to be in place in time to draft a legislative program that will be announced in Parliament on May 25.

Brown's departure follows three successive election victories for his center-left Labour Party, all of which were won by his predecessor Tony Blair, who ousted the Conservatives in 1997.