Mr Blair, who starts a visit to South Africa on Wednesday, told a British newspaper that Mr Mandela had already played a "unique and important role" in trying to resolve the controversy.

He said he would be asking him to intervene again to persuade Libya to hand over the two men suspected of the Lockerbie airliner bombing.

"I will explain that we have now done all we reasonably can to resolve the impasse over the trial", he said.

"The UK-US initiative for a trial in the Netherlands has been on the table for four months. I do not for one moment accept that Scottish courts would not give a fair trial, but was prepared to go for a third-country trial because this is what the Libyan Government said it wanted.

"I will appeal to President Mandela to convince the Libyan government that a third-country trial should now proceed."

Progress over trial

In August, the United States and Britain dropped their insistence that the Libyan suspects, Abdel Basset Ali el-Megrahi and Al-Amin Khalifa Fhimah, be extradited to either of their countries. They said the suspects could be tried before a Scottish court under Scottish law in the Netherlands.

The Libyan parliament signalled its backing of the deal in December. But Tripoli is demanding a number of guarantees before agreeing to allow the suspects to go on trial.

Libyan leader Colonel Gaddafi put a further question mark over the prospects for rapid progress when in an interview for Dutch television earlier this week he declared that an international court, with judges from the US, Libya, the UK and other countries, was the solution.

Libya is under UN sanctions first enacted in 1992 and reviewed every 120 days, including a ban on air travel, an arms embargo and a reduction in the level of diplomatic ties.

It could face tighter sanctions if it does not turn over the suspects by February when the Security Council's next review is scheduled.

Relatives hopeful

Swire: Heartened

A total of 270 people were killed when Pan Am Flight 103 blew up over Lockerbie on December 21, 1988. Eleven residents of the Scottish town were among the dead.

Relatives of the victims of the Lockerbie bombing are optimistic about prospects for a breakthrough in their 10-year quest for justice.

They are hopeful that the two Libyans accused of the bombing may be handed over for trial within weeks.

"Both Colonel Gaddafi and Libya's People's Congress (parliament) have said they accept the idea of a trial under Scottish law in Holland," said Dr Jim Swire, spokesman for relatives of the British Lockerbie victims.

"Libya wants this issue resolved. We feel we are still on course, we feel heartened by what's going on," he continued, saying he still believed that the suspects would be handed over within a matter of weeks, possibly in late January.