The trouble with double entendre is that you can’t keep pumping it out all night long without fatigue setting in. But, for the first third of Julian Clary’s live comeback show he proves himself still to be the master of his domain. In his first live show for five years he sets out his brand with commendable clarity. Introduced as “the commandant of camp, the meat and two veg of innuendo, the renowned homosexual”, he rollerblades on stage in a scarlet ringmaster’s outfit.

“I did Two Gentlemen of Verona here in 1984,” he reminisces. “They said they were from Verona, anyway.”

Clary sells his genteel filth with such smooth conviction that its relentlessness is part of its joy. “There’s a gag in every line,” he purrs, and indeed there is. As he switches from self-aware patter to talking about his time on Strictly Come Dancing, he’s in total control.

He talks about turning 50 — too old for alcopops, too young for Midsomer Murders — and moving with his boyfriend to the country, where Paul O’Grady is his neighbour. Keeping chickens provides him with fresh eggs — and, yes, fresh cock gags, too. So we know what kind of thing he’s going to say, but the quality of his writing means he retains his edge. Clary knows that even the best bum jokes won’t sustain a whole hour, so he’s mixed things up with a psychic routine. But a raunchier Derren Brown he is not. As Clary genially insults the front row, then brings on stage a pair of audience members, he loses focus. We’re left with nothing more than a mildly transgressive spin on the meet-the-contestants bit of The Generation Game.

Doubtless Clary will sell this section better as he builds up confidence on tour. Here, it’s horribly thin. And the big trick, in which Clary pulls down a sealed envelope, stuck to the back curtain throughout the show, and reads out all sorts of personal details about his volunteer, isn’t a big enough payoff. Certainly not in this auditorium, anyway, where a section of the crowd can see exactly how it’s done. Clary should sort out his sightlines before the Magic Circle sends out a hit squad.

So this charismatic performer’s show goes from great to good to weak. Some of that will change as nerves fade. But a self-awarded encore, in which he puts a gay spin on Frankie and Johnny, is desperately so-so, undersold by Clary’s sub-Rex Harrison non-singing.

The touring version will be half an hour longer. With luck that will mean more brilliant bitchiness, more meat-and-two-veg innuendo and less awkward gimmickry.

Unril Aug 30, box office: 0844 545 825. Tour from Sept 25: www.julianclary.co.uk