Tony Blair made a direct appeal to the Afghan people to rise up against the Taliban and complete the rout of their regime.
In both an emergency statement given to the House of Commons and a BBC World Service radio broadcast to Afghanistan, the Prime Minister said support for the fundamentalists was clearly "evaporating".
Mr Blair sought to encourage further uprisings by pointing out that there was a $25m (£17m) reward for information that could lead to the capture of Osama bin Laden. Under its "rewards for justice" programme, the United States has offered up to $25m for information that "prevents, frustrates or favourably resolves acts of terrorism against US interests worldwide".
In an interview with the BBC World Service, which was broadcast in Afghanistan, the Prime Minister said: "I believe there are people in Afghanistan who can help us. As you probably know, there are very substantial millions of dollars' worth of rewards for his [Mr bin Laden's] capture, for his yielding up to us."
The Prime Minister described Mr bin Laden as "not Afghan" and said he had "nothing to do with the Afghan people". He went on: "He and his people have abused Afghanistan over the past few years.
"They have made Afghanistan a haven for terrorist networks, exporting terror around the world, deeply reliant on the drugs trade. I think that many Afghan people will be glad to get rid of Osama bin Laden," he said.
In the Commons, Mr Blair gave details of the British forces that had been put on stand-by for deployment in the country and called on the Northern Alliance to avoid acts of revenge and to work with the United Nations.
Mr Blair said there would be an early UN-convened meeting of anti-Taliban groups, including Pashtuns, under the UN special representative to Afghanistan, Lakhdar Brahimi. The UK would restore its diplomatic presence in Kabul by the weekend, he added.
One result of the Taliban fleeing from key strategic cities was that the looming humanitarian crisis could be averted more easily, the Prime Minister said, with the World Food Programme now confident of meeting its objectives.
Insisting that talk of a tactical retreat was "a Taliban lie", Mr Blair told MPs the regime had obviously been "decisively defeated" in large parts of the country.
"It is clear that support for the Taliban is evaporating. Though there may be pockets of resistance, the idea that this has been some sort of tactical retreat is just the latest Taliban lie. They are in total collapse," he said.
When asked by Charles Kennedy, the Liberal Democrat leader, to condemn some of the atrocities committed by advancing Northern Alliance troops, Mr Blair agreed that restraint was vital.
"Regrettable incidents have happened as the liberated people have turned on their oppressors. This should not happen and I appeal to the Northern Alliance and all other forces to be restrained, to avoid acts of revenge and to engage with the UN," he said.
"I believe the whole House should welcome the progress that has been made. Though conflict is never easy or pleasant, to see women and children smiling after years under one of the most brutal, oppressive regimes in the world is finally to understand the meaning of the word 'liberation'."
Revealing that "several thousand" British troops were on stand-by, Mr Blair stressed that although they would be engaged in a range of duties, he could not "rule out some of our troops being used in offensive frontline operations".
On the humanitarian front, the Prime Minister said 2,000 tons of food a day were now getting into the country, four times more than at the beginning of last month.
Iain Duncan Smith, the Conservative leader, supported putting more British troops on stand-by and said the events of recent days had been a clear vindication of military action.Reuse content