The tale of the government minister’s office manager who used his online blog – written under a pseudonym – to smear political opponents reads like a pilot for an episode of In the Thick of It. This real-life episode, however, falls decidedly short on satire and comedy.

Unfortunately for Mark MacLachlan, former aide to Education Secretary, Michael Russell, instead of the claims he made about public figures triggering the comment and discussion he hoped, it is his anonymous smear campaign which has become the scandal.

Since he was revealed as “Montague Burton” one of many “cybernats” – who use websites to attack critics of the SNP – the most pressing question has been whether Mr Russell knew of his activities. The official answer from the minister’s office was a forthright denial and condemnation of the allegations.

That is now called into question by a series of emails exchanged between Mr MacLachan and Mr Russell, with the aide suggesting that the minister, whose portfolio at the time included culture and the constitution, not only knew about his blog but suggested ideas for it. In this case, Mr Russell still has some questions to answer.

Relaying damaging information has always been part of the cut and thrust of politics but the authors of unattributed internet postings assume that their cloak of anonymity is a shield against prosecution and therefore feel free to blur the line between allegation, unfounded gossip and speculation. Blogs based on well-founded information, on the other hand, can be seen as the internet version of the long tradition of political satire.

It is in the public interest to expose public figures guilty of lying or hypocritical behaviour, and since the most effective defence against defamation is truth, all that’s needed is the evidence. When allegations cannot be substantiated, journalists and responsible authors, bloggers included, investigate to discover the truth.

The Westminster blogger, Guido Fawkes forced the resignation of Damian McBride, one of Gordon Brown’s aides, after obtaining an email correspondence between him and the Labour activist Derek Draper suggesting a campaign of personal smears against senior Conservatives.

Any politician who seizes upon blogging as a new tool in the dark art of political spin must apply the same rules as they would to public statement or be prepared to pay a high price for revelation of their involvement.

If the unmasking of “Montague Burton” and Damian McBride as the politically-motivated authors or plotters of defamatory claims on the internet has the effect of injecting accountability into the blogosphere, it will be to the benefit of all who value truth over political expediency.