Brown leads tributes to Obama

Speaking from No 10, the Prime Minister declared: "This is a moment that will live in history as long as history books are written."

Mr Brown described Mr Obama as "a true friend of Britain", while emphasising their shared commitment to "progressive" politics.

"I know that the values we share in common and the policies we work on together will enable us, these two countries, to come through these difficult economic times and build a safer and more secure society for the future," he said.

"I hope to be able to work with Senator Obama to bring the world together so that we can face these difficult times with more co-ordination and more unity than we've seen before."

Tory leader David Cameron also sought to align himself and Mr Obama as one of a new generation of political leaders who were ready to change the world. "In these difficult times people everywhere are crying out for change. Barack Obama is the first of a new generation of leaders who will deliver it - he has my whole-hearted congratulations," he said. "This is an important moment not just for America but for the world."

Liberal Democrat leader Nick Clegg said that the world would now be looking to Mr Obama for a "radical new approach" that would leave the Bush era firmly behind. "British voters may not have been able to vote in this election, but its outcome is vital to our future," he said.

Across the Channel, French President Nicolas Sarkozy, who currently holds the rotating EU presidency, said that Mr Obama's "exceptional" campaign had underlined the vitality of American democracy. "By choosing you, the American people have chosen change, openness and optimism," he said. "At a time when all of us must face huge challenges together, your election raises great hope in France, in Europe and elsewhere in the world."

The tributes were not confined to the world of politics. Lewis Hamilton, newly crowned as the first black world champion of Formula 1, also offered his congratulations to America's first black president.

"I'm very happy. I tried to watch it as much as I could," the McLaren driver said on his return to the team's headquarters in Woking, Surrey. "I have a huge amount of respect for the candidates and I was very happy and proud to see Obama at the front and congratulations to him."