Dr Jim Swire: It will happen we just don't know exactly when

Spokesman Jim Swire said: "I don't know when it's going to happen, but I am convinced that it's going to happen and within weeks."

He was speaking ahead of a meeting of the Libyan parliament, the General People's Congress, which could finally approve a deal to hand over the suspects.

The meeting is due to start on Tuesday, but it may be several days before the issue is debated.

Dr Swire: A deal within weeks

The move follows a "positive and fruitful" meeting between the United Nations Secretary General, Kofi Annan, and the Libyan leader Colonel Muammar Gadaffi at the weekend.

During the talks the colonel reaffirmed Libya's agreement for a trial to take place in Holland.

However, final approval of the deal appears stalled over the issue of where the suspects would serve their sentences if convicted.

Anniversary

UK Foreign Secretary Robin Cook has expressed hopes that the suspects could go on trial by 21 December, the 10th anniversary of the bombing in which 270 people died.

Mr Annan was "cautiously optimistic" after his Libyan trip

However, the Libyan state news agency has said no hand over would take place in time for the anniversary.

But an unnamed Libyan Foreign Ministry official was quoted as saying "a solution to this crisis is within reach".

Dr Swire said he wanted to see a speedy resolution, but he hoped that pressure to move the process along would not sabotage an agreement.

"I would love it to happen before Christmas," he said.

"But I am very worried that the Americans will start making aggressive noises if it doesn't happen by the 10th anniversary. I think that would be counter-productive. Diplomacy doesn't work well against a background of a deadline."

Mr Cook emphasised that 21 December was not a deadline, but said relatives of the dead would find the anniversary easier to cope with "if they knew the suspects had been surrendered and there's a real prospect of the facts coming out in the open".

A breakthrough became possible this summer after the UK and the United States dropped their insistence that Abdel Basset Ali Mohammed al-Megrahi and Lamen Khalifa Fhimah should stand trial in Scotland.

Sticking point

Instead they have agreed to a trial in the Netherlands under Scottish law.

BBC Diplomatic Correspodent Barnaby Mason: It is not clear what the Libyans will do next

However, Libya is still resisting Britain and America's insistence that the suspects should serve any sentence in Scotland, despite assurances that Libyan representatives would be allowed to monitor the men's conditions.

Washington and London have shown no sign of compromising on this issue.

Mr Cook said: "I see no reason why they should serve their sentence anywhere else other than where the crime was committed.

"If they are convicted, the logical place for them to serve their sentence would be Scotland."

BBC Diplomatic Correspondent, Barnaby Mason, says the issue could still provide the sticking point that leads to hopes of a trial being dashed again.

Key facts on Lockerbie
Profile: Muammar Gaddafi, Libyan maverick
Profile: Kofi Annan, Master of diplomacy