The Defence Secretary, Mr Geoff Hoon, has confirmed Britain's readiness to deploy thousands of troops as part of an international stabilisation force inside Afghanistan.
At the same time Mr Hoon has suggested that should British forces capture Osama bin Laden he would only be handed over for trial in the United States given an assurance that he would not face the death penalty.
However, British sources last night said privately the possibility was entirely theoretical and that the potential legal complications between the US and Britain meant any capture would be in American hands.
Pressed to say what would happen if bin Laden was captured by British personnel, Mr Hoon said he would be handed over "fairly promptly" to face justice in the US and explained the existence of the death penalty there need not be a bar. He added that it would be very important "to respect the international legislation relevant to those circumstances".
He continued: "We do extradite people to certain countries with the death penalty, obviously subject to certain undertakings. I see no reason in principle why that shouldn't happen. I would mean, of course, that certain undertakings would have to be given about any penalty he might face."
Asked if this meant the US would have to provide assurances that bin Laden would not face execution, Mr Hoon replied: "That is the position." The Defence Secretary's reply is understood to have been based on clear legal advice and reflects something of the different legal frameworks within which American and British forces are required to operate in the field.
Mr Hoon refused to comment on the possible scale of any British commitment to a peace-keeping force in Afghanistan before tomorrow's talks on the issue with the US Secretary of State, Mr Colin Powell, in London. But he played-down one report suggesting as many as 10,000 troops might be sent, saying: "I don't necessarily believe any one country will have such a large number."
Meanwhile the Home Secretary, Mr Blunkett, was accused of "bullying" yesterday after warning the Tory leader, Mr Iain Duncan Smith, of the "dangerous consequences" of continued opposition to elements of his anti-terror Bill in the House of Lords. If concessions offered on Friday fail to break Tory and Liberal Democrat resistance, Mr Blunkett intends to use the government's Commons majority to over-rule all the Lords amendments when the Bill returns to the Commons on Thursday.