The UK Government has offered further reassurances to Libya about the conditions in which two Libyans suspected of carrying out the Lockerbie bombing would serve a prison sentence if convicted.

Britain said on Tuesday it was prepared to make special arrangements for the prisoners and that there would be an international observer regime to ensure that they were treated properly.

The government has already clarified a number of points about the proposed trial through the office of UN Secretary-General Kofi Annan.

The remaining sticking point appears to be Libya's demand that the two suspects, if convicted, should not be imprisoned in Scotland - something both Britain and the United States insist on.

Now Britain has offered to make special arrangements for any prisoners.

Unlimited access

International observers would have automatic and unlimited access to ensure they are treated properly.

Mr Annan would also be able to appoint a special representative to co-ordinate the regime with the authorities.

Colonel Gaddafi: "No more conditions"

In addition, Libyan diplomats would have unlimited access to the prisoners. The diplomats could be based at a Libyan consulate to be opened in Scotland.

The disclosure of these assurances at this point is clearly designed to increase the pressure on Colonel Gadaffi to accept the deal and to demonstrate to Africa and the Arab world that Britain has done everything that could be expected of it.

British officials also reaffirmed the UN Security Council position that sanctions against Libya would be suspended, though not lifted outright, as soon as the two Libyans have been handed over for trial in the Netherlands.

On Sunday Colonel Gadaffi said the trial could happen only if Britain and the United States stopped imposing conditions.