Harry Hill's I Want a Baby makes Vicky Pollard look like sophisticated satire

Well, it is certainly not Julie Andrews singing My Favourite Things. It's hard to know why comedian Harry Hill decided to release the blood-curdlingly bad single I Want a Baby - which pokes fun at working class culture from pit bulls to pink tracksuits via digs at teenage pregnancy, ASBOs and Kerry Katona. It is a mean, sneery off-the-dial insult of a song that makes Vicky Pollard seem like sophisticated satire and a Daily Mail editorial a shining beacon of enlightened liberal thinking. If it is meant to be knowingly affectionate, any ironic winks were lost in the edit.

While this may not be Sachsgate – Chavgate, perhaps – I Want a Baby may well have dented Hill's credibility, sending Twitter into a tizzy and forums into a frenzy. I've always enjoyed Hill's mix of music hall, surrealism and smart off-the-wall one-liners – "why is it only Tudor buildings we mock?" – and TV Burp is one of only a few genuinely laugh-out-loud programmes. It is populist, intelligent and, amazingly, on Saturday nights on ITV1. The former doctor with the trademark massive collars has pulled off the rare trick of going from cult to primetime without dumbing down. Until now. This ditty about the fictional 14-year-old Chantelle – "Me mum has got a fag on, me dad has got a tag on" – is in danger of losing the very fans that have discovered him on the mainstream channel.

Comedy has had a habit of poking fun at the post-Shameless underclass for some time now. There's Vicky Pollard, of course, BBC3 uber-chav Lee Nelson and, on BBC2, Harry & Paul have a running gag featuring the Benefit family, who roam the streets with their devil dog. These jokes, all by smart, middle-class wags, can certainly be clever pieces of social commentary – Ali G managed it – but I Want a Baby feels devoid of insight. There have been hints of Hill's growing tendency to look down on the unfortunate in his fashion taste-teasing You've Been Framed voiceovers, but that did not prepare me for this.

It's not that Hill has completely lost it. He has just launched his own lo-fi internet-only series via AOL, which harks bark to his C4 golden era of badger parades and Stouffer the Cat. But sometimes even the canniest comedians misjudge the mood. It was as if alternative comedy had never happened when Al Murray created his camp, pink uniform-wearing Nazi, prompting an outcry. Let's hope Hill listens to the protests this time. Johnny Marr reportedly refused to give Hill permission to include a Smiths medley on his forthcoming album of comedy cover versions, Funny Times. At the time I thought it was Marr who had had a sense of humour failure. Now I think it is Hill.