RADIO: Caesar's chum: Whenever Robert Hanks tunes in, there is David Mellor. It's not that he's bad, but is he any good?

Back in 1961, when John Osborne wrote A Patriot for Me (Radio 3, Sunday), the Lord Chamberlain's office requested a series of cuts to make this story of Viennese fin-de-siecle decadence, snobbery, treachery and, in particular, homosexuality acceptable to the listening public. Osborne got round this by having the play staged at a private theatre club, indirectly helping to bring about the end of the Lord Chamberlain's reign over British theatre. (Although - and this is not generally known - he did also produce a version of the play trimmed to satisfy the Lord Chamberlain's demands, which later became an episode of Pogle's Wood.)

Attitudes to what may or may not be represented on stage have changed considerably since A Patriot for Me; on the other hand, the prurient morality it depicts is pretty much intact, with sexual misdemeanours still considered a grave enough drawback to holding public office for ministers to be driven underground. We probably ought to be pleased that society has advanced far enough for a disgraced minister to come back as a successful media figure (John Profumo, for instance, was never allowed to fulfil his lifetime ambition to host Come Dancing). But somehow, listening to David Mellor on all channels, it's hard to muster a smile.

In the last few days you could have heard the former heritage minister chairing the intendedly controversial chatter on Soapbox (Radio 4, Thursday), schmoozing Lord Harewood on Vintage Years (Radio 3, Saturday) and buttering up the footballing public on the phone-in Six-Oh-Six (Radio 3, Saturday) - only Simon Bates (you remember him) has ever managed to ride the airwaves to quite this extent, and even he didn't do it all at once and hold down a regular column in the Guardian and a parliamentary constituency.

He has a basic competence as a radio presenter (a rarer quality among radio presenters than you'd like to think), and he knows his way around a football pitch and an opera house. He has his fans - every so often a caller on Six-Oh- Six will say that he votes Labour but still thinks David is doing a great job. But he's not that good - so good that he should be everywhere. He is both too self-regarding (a reference on Six-Oh- Six a couple of months ago to 'two of the most famous gap-toothed grins in Britain' turned out be a way of introducing a conversation between Jimmy Tarbuck and himself), and too deferential, flattering his audience constantly, enthusing about their eloquence and frequently sliding into an implausible demotic, sprinkled with glottal stops, 'mates' and folksy phraseology ('You and me both, brother'). He's not to blame, perhaps: he's a politician, and that's what they do. But it's partly because he's a politician that you wonder about the appropriateness of having him present so many programmes. (Let's be even-handed here: you also wonder how fitting it is to have Glenys Kinnock present The Unfamiliar Family on Radio 4 on Thursdays, a series about the relationship between politics and family life, given her own family connections and public ambitions to become a Labour MEP.)

James H Reeve cottoned on to the basic difficulty on Soapbox this week, when a discussion of phone-boxes prompted David Mellor to read out a note from BT boasting about the number of pay-phones they'd installed in the last five years: Reeve accused him of making a disguised plug for privatisation, and his worry was understandable. Simply because he's a serving politician, there's always a slight sense that when David Mellor is on air, he doesn't just work from a running order; he's got another agenda tucked up his sleeve. You don't have to believe that broadcasters should be like Caesar's wife, above suspicion, to feel that there's something amiss when they're well-known as one of Caesar's chums.