Professor Robert Black, one of the original architects of the trial at Camp Zeist, and Hans Koechler, the UN observer at the original trial, are putting together a list of signatories to persuade the General Assembly to establish a commission to investigate.

Dr Jim Swire, whose daughter Flora died in the tragedy, and Father Patrick Keegans, the priest in Lockerbie at the time of the bombing, have already backed the move.

Only one country would be required to endorse such a commission and, unlike in the case of the Security Council, there is no right to veto such a project. The hope is to get an inquiry established once Libya takes over presidency of the General Assembly later next week.

Such a commission could not compel other countries to co-­operate but could publicly name and shame them.

The news comes as Downing Street denied trying to conceal details of Gordon Brown’s talks on the Lockerbie bombing with Barack Obama after it confirmed it was the Prime Minister -- and not the US President -- who had broached the subject earlier this week.

Abdelbaset Ali Mohmed al Megrahi, who has consistently denied his involvement, was serving a 27-year sentence in Greenock prison. He was released early on compassionate grounds because he is suffering from terminal cancer. His second appeal, which campaigners believe would have cleared his name, was dropped last month before he returned to Tripoli.

Professor Hans Koechler,

Professor of the University of Innsbruck, said the General Assembly had set up such a commission in 1968 to look at Gaza.

He said: “As the General Assembly is a deliberative body it has only moral authority and no coercive powers. It could however raise international awareness of the different issues involved and name and shame certain countries enough to ensure they do something about it. It could pressure Britain into holding an inquiry.”

While Kenny MacAskill, the Justice Secretary who made the decision to free Megrahi last month, has said he would support a UK inquiry into the Lockerbie bombing, Westminster has consistently refused.

The Scottish Parliament’s Justice Committee is investigating the circumstances surrounding the decision to free Megrahi but many of the relatives and those involved strongly believe the whole case -- from beginning to end -- needs to be scrutinised.

Dr Swire, said: “We are preparing something to send to the UN General Assembly and looking to get people to sign up to it.”

A petition is also being prepared to persuade the Prime Minister to back an inquiry in Westminster.

Other relatives of the victims have suggested there could also potentially be an application to, and another reference from, the Scottish Criminal Cases Review Commission (SCCRC) to refer the case back for a third appeal.

Professor Black, who is supporting the application to the UN, said: “Theoretically, there could also be another application to the SCCRC -- particularly as the commission has already said this may have been a miscarriage of justice on six separate grounds.”

Colonel Muammar Gaddafi takes over the rotating presidency of the UN General Assembly later this month.

Professor Robert Black