Libya is set to flaunt the Lockerbie bomber’s release at the climax of today’s celebrations marking Colonel Muammar Qaddafi’s 40 years in power.

The Times of London gained access last night to the dress rehearsal of a spectacular two-hour show which extols Colonel Qaddafi for reviving his country and restoring Arab pride. As the finale approaches, the screen at the back of the giant stage in Tripoli’s Green Square shows Abdul Baset Ali al-Megrahi stepping off the plane which brought him home from his Scottish prison two weeks ago. His arms are raised aloft by Colonel Qaddafi’s son, Saif, as he acknowledges the joyful reception from the crowd below.

Unless it is cut out at the last minute, the clip’s inclusion seems almost calculated to provoke the West. Britain and America had urged Libya to keep al-Megrahi’s homecoming low key, and President Obama and Gordon Brown both expressed disgust when he was given what appeared to be a rapturous welcome at Tripoli airport. It also flies in the face of repeated assurances by Libyan officials, including Saif Qaddafi, that the reception was muted and not intended as a display of gloating. Al-Megrahi himself is now in hospital, seriously ill with prostate cancer.

Anxious to dampen down the controversy caused by al-Megrahi’s release, Britain is expected to send only a junior representative to today’s ceremonies. The British Embassy in Tripoli said that Sir Vincent Fean, the ambassador, was in Malta, suggesting the job will be left to a more junior diplomat. “We are still considering the level of representation,” a spokesman said.

Other European states are sending ministers, ambassadors or official delegations, but the President of Malta is thought to be the only European head of state attending. However the audience will include a large number of African leaders and Venezuela’s President Hugo Chavez.

In another development yesterday, Libya linked its cooperation in the unsolved murder of WPC Yvonne Fletcher in 1984 to Britain helping its investigation of a 1996 assassination attempt against Colonel Qaddafi allegedly financed by MI6. “These two cases are linked,” Mohammed Siala, a member of Colonel Qaddafi’s cabinet, replied when The Times asked if Libya would show WPC Fletcher’s family the compassion shown to al-Megrahi by surrendering her killer.

WPC Fletcher was shot during a demonstration outside the Libyan Embassy in Central London, almost certainly by a bullet fired from the building’s first floor. Her killer was thought to have been smuggled out of the country. As Libya shed its pariah status Metropolitan police officers visited Tripoli in 2004, 2006 and 2007.

The assassination attempt to which Mr Siala appeared to be referring occured when Colonel Gaddafi’s motorcade was attacked in the town of Sirte. He survived but six bystanders were killed. David Shayler, a renegade MI5 officer, later claimed that MI6 had paid the so-called Islamic Fighting Group £100,000 to stage the attack.

Mr Siala denied his government was upset that so few Western leaders were attending today’s celebrations, which are supposed to mark Libya’s return to international respectability. “It’s up to them to come or not,” he said. But he did complain that the West had not responded adequately to Libya’s renunciation of terrorism and weapons of mass destruction.