New British Prime Minister David Cameron unveiled more details of his historic centre-right coalition on Wednesday, vowing "strong" government after ending 13 years of Labour rule.
The 43-year-old, Britain's youngest prime minister for two centuries, got down to work in Downing Street after striking a deal between his Conservative party and the third-placed Liberal Democrats late Tuesday.
Cameron, who has radically transformed his Conservative party from the Margaret Thatcher years, announced a series of cabinet appointments, including Lib Dem leader Nick Clegg as deputy premier and four other Lib Dem ministers.
New Foreign Secretary William Hague insisted the coalition agreement, forged in five days of political deadlock after an inconclusive election, would stand the test of time.
"I don't think it will be a weak coalition. It will be a strong government," said Hague, adding that the conflict in Afghanistan, where Britain has around 10,000 troops, would be his "most urgent priority."
New Finance Minister George Osborne added: "Now's the time to roll up the sleeves, and get Britain working."
London's stock market and the pound recovered after a jittery few days ended with Tuesday's deal to form Britain's first coalition government since World War II, following the first hung parliament since 1974.
"Markets had feared a negative start, but as the dawn of a new political era takes place, there appears to be a collective sigh of relief that we have a clearer way forward," ODL Securities trader Owen Ireland said.
Cameron's appointment by Queen Elizabeth II on late Tuesday came after Labour leader Gordon Brown finally admitted defeat.
Cameron acknowledged the huge challenges facing him, not least Britain's fragile recovery from the global economic crisis.
"This is going to be hard and difficult work. A coalition will throw up all sorts of challenges," he said in a speech in Downing Street, flanked by his pregnant wife Samantha.
US President Barack Obama called Cameron within minutes of his appointment, inviting him to visit the United States in July, Downing Street said.
On Wednesday Chinese Premier Wen Jiabao had a 15-minute conversation with him, while Indian Prime Minister Manmohan Singh invited him to make an "early" visit to Delhi, Downing Street added.
French President Nicolas Sarkozy is to hold talks with Cameron in a visit on June 18.
Other leaders including German Chancellor Angela Merkel and Australian Prime Minister Kevin Rudd also quickly called Cameron to congratulate him.
European Commission chief Jose Manuel Barroso said Cameron's government would face "difficult choices in difficult times", while Russia said it hoped for a "new impulse" in chilly relations.
Clegg was joined by four other Lib Dem ministers in Cameron's coalition government -- including his respected finance chief Vince Cable as business secretary.
"We are going to form a new kind of government," Clegg told his lawmakers, adding he hoped it marked "the start of the new politics I have always believed in."
Key Conservative appointments included 38-year-old Osborne as finance minister, Hague as foreign minister, and Liam Fox as defence secretary.
Britain lived through five days of uncertainty after Thursday's general election.
The Conservatives won 306 seats in the 650-member House of Commons, 20 short of a clear majority of 326, followed by Labour on 258 and the Lib Dems on 57. The Lib Dems held talks with both Cameron and Brown's party.
Clegg is leading a Liberal party into British government for the first time since David Lloyd George left power in 1922.
Critics say the deal between the centre-right Conservatives and centrist Lib Dems is an unlikely alliance, since they have strongly differing views on a number of issues.
But between them, they have enough to secure a majority in the House of Commons which Labour and the Lib Dems, seen as more natural bedfellows, did not.
There were already doubts about the political union on Wednesday, however, with the Conservative-supporting Daily Telegraph newspaper warning it would be "unsatisfactory and short-lived."
Brown wished Cameron well as he left office on Tuesday, while acknowledging the personal weaknesses, such as poor presentational skills and impatience, which hampered his three-year premiership.
A leadership campaign to replace him is expected to conclude by September.