On the eve of the fifth anniversary of the terrorist attack, Tam Dalyell said ministers' repeated assertions that Libya alone carried out the bombing, looked 'highly suspect' after the disclosure that 'vital evidence' challenging Libya's role was uncovered three years ago.
Baroness Thatcher's recent denial that Libya carried out the attack, he added, 'strongly suggests that the Government has suppressed the facts in a bid to pin the blame on Colonel Gadaffi and let Syria and Iran off the hook because the two countries are now vital allies in the Middle East'.
When Britain and the US issued arrest warrants in November 1991 for the two alleged Libyan intelligence agents accused of the bombing, officials insisted that Libya alone was involved. But this week a key witness in the Lockerbie investigation has said that he told British detectives in 1990 that the bomb's timer, which investigators thought was made exclusively for Libya, had been more widely available.
In a BBC Radio File on Four interview to be broadcast today, Ulrich Lumpert, who was chief engineer at the Swiss firm that manufactured the timers, says: 'I told the police that the first two had gone to East Berlin. They wrote down what I told them.'
Mr Dalyell said: 'The case against the two Libyans hinges on the timers being exclusively available to Tripoli. If Mr Lumpert told police three years ago that identical timers could be obtained elsewhere - and there is no reason to doubt what he says - it is inconceivable that the Government would not have known . . .'
In her Downing Street Years memoirs, Lady Thatcher says that after US jets bombed Tripoli in 1986 'there was a marked decline in Libyan-sponsored terrorism'. Mr Dalyell said: 'Mrs Thatcher says Libya did not carry out the Lockerbie bombing. As the (then) head of the intelligence services she should know. If you add her evidence to that of Mr Lumpert, ministers' statements begin to ring rather hollow. It looks like a cover-up to protect strategic British and American interests.'