Our man in Kabul: Karzai installed as Afghan president

Mr Karzai was officially declared the victor in an election in which he was the only candidate yesterday after his sole challenger Dr Abdullah Abdullah pulled out of the race.

Prime Minister Gordon Brown joined the unseemly throng to congratulate Mr Karzai on his re-election, backing the cancellation of the second round run-off.

"The government welcomes the decision by the Independent Electoral Commission," a No 10 spokesman said.

"The Prime Minister has spoken to President Karzai to congratulate him on his re-election. They discussed the importance of the president moving quickly to set out a unifying programme for the future of Afghanistan."

Lindsey German of Stop the War Coalition was scornful of the result and the welcome it received. She said: "It is absolutely farcical. It was a fraudulent election first time round and this time it is pure farce.

"Karzai's credibility is no better than it was when he lacked the 50 per cent required in the first round.

"This just exposes what we have said all along - that this war is not about democracy, it's about protecting a corrupt government.

"Whatever next?" she asked. "The US and Britain spend all their time complaining about rigged elections elsewhere in the world and this one was manufactured in the US and UK."

Ms German said it was disgraceful that British troops had been dying throughout the summer to defend the Karzai regime.

"The only way we are going to stop this is to pull the troops out now and expose this corrupt regime for what it really is," she said.

There was widespread evidence of mass vote-rigging during the first round of the poll in August, meaning a second round of voting was necessary.

That vote was due to take place on November 7, but this weekend an emotional Dr Abdullah announced he was pulling out of the race saying conditions had not been met for a free and fair poll.

Despite attempts to put a brave face on the situation, the outcome will not be entirely satisfactory for the international coalition.

President Karzai has suffered further damage to his already shaky credibility having emerged with a deeply flawed mandate.

He is now likely to face international pressure to shore up his legitimacy by forming some form of government of national unity with Dr Abdullah.