Andrew Marr has apparently been rude about bloggers. He said: A lot of bloggers seem to be socially inadequate, pimpled, single, slightly seedy, bald, cauliflower-nosed, young men sitting in their mother's basements and ranting. They are very angry people.

I don't know why Andrew thinks my spottiness or otherwise is of any relevance. And I won't lower myself to Mr Marr's level by characterising his own appearance. Instead I will stick to the real issue.

Andrew Marr obviously considers himself to be a good journalist. Presumably the BBC also thinks highly of him, as he was the person chosen to front their impartiality seminar a few years ago, which resulted in From Seesaw to Wagon Wheel, previously discussed by this blogger on several occasions.

Mr Marr said then that "The BBC is a publicly-funded urban organisation with an abnormally large proportion of younger people, of people in ethnic minorities and almost certainly of gay people than the population at large.

"It depends on the state's approval at least for its funding mechanism and all this creates an innate liberal bias inside the BBC ...." When I asked about the evidence upon which his remarks were based, Andrew simply ignored all correspondence.

Here is the text of my penultimate email to Mr Marr, dated 28 March 2010:

subject Re: BBC Impartiality Summit

I must confess that I'm getting rather concerned about the fact that you have not yet responded in any way to my several emails. On the basis of your integrity as a journalist, I now look forward to a reply. Many thanks.

The BBC has now published its new editorial guidelines. Newsround Blog will comment more in due course.