Sketch: you can elect a new Mayor but you can't get rid of Ken

As the Assembly members strode in to put Boris Johnson through his paces, a ghostly figure in beige descended on the front row of the gallery.

Yes, you can vote Ken out, you can give his successor the mayoral seal and empty his filing cabinets - but that doesn't mean you can get Ken out of the mayoral offices.

He settled in like one of those elderly souls who attend public meetings with a flask of tea and a rug. Is it part of the grieving process or the earliest comeback attempt on political record?

Mr Livingstone wasn't saying. "I'm here to hold the Mayor to account," he said. Funny how keen they become on the accountholding thing when they're no longer the ones facing scrutiny.

So off we went. Mr Johnson, in an expensive black suit for his first big outing, got a cycling helmet from a Labour member. But he revealed that he'd just bought one anyway, the better to protect his anonymity. There is of course as much chance of Heather Mills seeking anonymity as Mr Johnson opting for a life of obscurity.

Nothing is so trivial that the Assembly and the new Mayor cannot disagree about it at great length. So Mr Johnson likes the sound of boxing academies to teach tough kids a little learning with their right hooks.

Someone immediately started fretting about the suitability of pugilism for the capital's youth.

Mr Livingstone, whose suit has not been ironed since election night, raised his eyes to the heavens and I knew how he felt.

John Biggs, a Labour pugilist, was setting himself up as Mr Johnson's nemesis. He belted him round the ring on perceived lapses in the Mayor's first appointments. Could it be that Boris was riding roughshod over the rules when it came to the appointment of a former council leader as his adviser? "You're not some Oliver Cromwell who can make up the rules as you go along," pestered Mr Biggs. Mr Johnson is on thin ice here and it showed. He has spent a lifetime making up the rules and clearly sees no reason to change.

Now and again, the new BNP member, Richard Barnbrook, shouted some interjection or other. After an hour or so Mr Johnson got bored and replied in Latin. It's a party trick some of his admirers relish. It does not go down so well in a gathering of the clipboard classes of Tooley Street.

Nicky Gavron, the continuation of the old Mayor by more glamorous means, had a heavy duty question about environment and planning up her designer sleeve.

Mr Johnson promised cooperation. Miss Gavron promised even more cooperation by way of reply. That's nice then.

Mr Livingstone allowed his much furrowed brow to sink quietly into his hands. Rather like the rest of us, he was surely thinking that it's not much fun in City Hall - unless you're running it.