Hello, you are through to the Scottish Executive. The central inquiry line is now closed.

Normal office hours are 8am to 5pm, Monday to Friday. However, if your inquiry is urgent, please hold and you will be put through to the security control room."

That is what UK Ministry of Justice officials would have heard when they were supposed to have called on May 25 to inform Alex Salmond and the Scottish Executive about the secret talks with the Libyans over the fate of the Lockerbie bomber, Abdelbaset Ali Mohmed Al Megrahi. Whitehall claims that attempts were made to contact Scotland, but it was a bank holiday and no-one was home.

Well, had the ministry officials held on for just 30 seconds, they would have been put through to the duty officer at the Scottish Executive. I tried it myself yesterday. For, of course, when it comes to running the country, there is never simply "nobody home". There are always officials on duty, in case of emergency, and ministers can be contacted at home on their mobile phones.

The claim that "attempts were made" to contact the Scottish Executive is so ridiculous that I can hardly believe that Whitehall officials are serious in suggesting it. It is even more disturbing that some sections of the Scottish press appear to accept it as a valid explanation of what happened - that it was a cock-up rather than a conspiracy. Yet London could easily have contacted someone in the Scottish Executive that Friday. The sheer cynicism of this explanation is an insult to the intelligence of Scots, and an affront to the Scottish media, who are being treated as complete idiots.

From the moment this story broke, Downing Street and the Scotland Office have been trying to manipulate the truth. I won't say they have been lying, but their economy with the truth amounts to wilful distortion. First of all, we were told that the memo of understanding, signed by Tony Blair in a tent in the Libyan desert last month, "specifically excluded" Abdelbaset Ali Mohmed Al Megrahi. We now know that it did not exclude Megrahi.

Then we were told that it had been made clear to the Libyans during the talks that any deal could not include Megrahi. This is untrue. Official sources in the Libyan government confirmed to The Herald that the memo was clearly intended to cover the Lockerbie bomber, and that this was explicit in the transactions in the desert. The Sunday Herald has discovered that British officials actually told their Libyan counterparts that Scotland was a "minor complication" over prison transfer that Libya need not "worry about".

And the Sunday Times reported yesterday that Libyan consular staff had even visited Megrahi in Greenock prison to tell him that diplomatic efforts were under way to have him transferred. In other words, the Lockerbie bomber was told even while the Scottish Executive was being kept in the dark.

The former Labour minister, Brian Wilson, has said that "the only fact that matters" is that the Scottish Executive would have had to give explicit approval before Megrahi could be transferred from Scottish custody. That isn't really true, either. It is not at all clear, under the Scotland Act, that the Scottish Executive could have blocked the move. The Foreign Office could have argued that this was part of an international treaty, and could have cited the constitutional primacy of Westminster.

But even if it had intended to secure Scottish approval, it still beggars belief that Downing Street did not keep the Scottish law officers and the First Minister informed of what was going on. It seems the decision not to call was taken by the Prime Minister himself. The Sunday Herald revealed yesterday that senior officials at the Foreign and Commonwealth Office advised Tony Blair that he should tell Alex Salmond about the deal over Megrahi.

Which brings us to the final piece of misinformation - the claim that the Scottish Executive had been informed about the diplomatic moves on prisoner transfer on May 25. I was assured that this was the case by a senior UK government source last week. When I asked who had been contacted and what had been said, I was told that no-one actually knew, "but the attempt had been made" to contact the Scottish government. Needless to say, the Scottish Executive has no record of any call.

Now, some in the Scottish media seem to believe that this is a storm in a tea cup, and that it's time to move on. Well, I'm sorry, but this is too important to let go. There was a pattern to events which betrays a shocking degree of disrespect to the Scottish government and to the Scottish people, who were not told the truth about this affair, and are still not being told it.

The people who concocted this misleading account of events need to be held to account, and the UK government should be required to tell the whole truth about this affair. The Foreign and Commonwealth Office should issue an apology to the Scottish law officers for failing to inform them of the transactions with Libya, and the Scottish Executive must receive an assurance that nothing like this will happen again.

This is basic issue of trust. If Downing Street really wants to clear this matter up, it should issue a clear statement to the Libyan government revoking the memorandum and making it absolutely clear that Megrahi will, under no circumstances, be transferred, either to Libya or to another Muslim country. That he will serve out his 27-year sentence in a Scottish jail.

But why, you ask, would Downing Street concoct a story that was so patently ridiculous that no-one could possibly believe it? Well, one plausible explanation is that Downing Street felt it had to prevent, at all costs, the story breaking in London. It would have been highly damaging, not just to relations with foreign countries, but to the government's anti-terrorism policy if it had become known that Tony Blair had been in secret negotiations with the Libyan dictator over the possible transfer of the man convicted of the worst ever terrorist atrocity on British soil.

The government killed the story in London by assuring the UK press that the story was pure invention by a Nationalist First Minister determined to pick a fight with London. They knew this was untrue, but felt they were "lying for Britain". This interpretation was accepted by the BBC Newsnight programme and informed the now infamous interview by Kirsty Wark, for which the BBC subsequently apologised.

What infuriates me most about this whole affair is the implication that anyone who questions the Downing Street account is a Nationalist sympathiser. Well, I belong to no party, but I can tell this this much: if they want to hand the political initiative to the SNP, they are going exactly the right way about it. And I say this to UK government sources: in future, don't ring me unless you are prepared to tell it straight. You might find I am not at home.