Paul Merton has been a TV and radio regular for so long that it was a real pleasure to see him live at the New Theatre on Tuesday. He arrived with his ‘Impro Chums’ for an extended session of improvised comedy and it was an evening of extraordinary intellectual brilliance.

The chums are his wife, actor and comedian Suki Webster, Mike McShane — the solidly-built comedian we first came to know years ago on Whose Line Is It Anyway? — and two stalwarts from London’s Comedy Store — Richard Vranch and Stewart Lee. They loped on to the stage and launched straight into the classic improvisation routine of calling out to the audience for ideas around which they could weave wonderful chaos.

Thus McShane as a dog psychiatrist and a pole dancer. Thus Webster leaving the auditorium so that we could suggest that she be a professor of unusual back flips in a circus in Japan wearing a codpiece and the others having to act out the answers for her. Thus ten superb minutes of Merton and Lee linking the Welsh with sheep dogs. The first half ended too soon with an extended stop-go drama that switched styles from horror to musical to gangster to interpretative dance to G & S to silent film — all about frogs!

During the interval, we were asked to fill a couple of buckets with notes suggesting situations which the ensemble could perform at random. They were quite marvellous at picking up on a truly impressive list of Oxonian suggestions — chief among them Nick Clegg in the confessional (history will record the importance of such political coverage on this specific evening), Mike Tyson does drag, Joan Collins on an oil rig and, crucially, an opportunity for Mike McShane to impersonate a bogey drying out on a window sill.

Impossible to sum up for those who weren’t there. Sorry.