Russell Brand is at it again. No, not clogging up the tabloids with his sordid-yet-saucy bedroom antics, but making another film. Brand is to play George Wickham in a comedy remake of Pride & Prejudice, also said to be starring Lily Allen as Lydia Bennet. This is an odd bit of casting – if this is a send-up of the literary classic surely Brand would have made a wonderfully sleazy Mr Darcy, emerging from the lake in soaking wet see-through trousers rather than a see-through shirt.

Brand is clearly pursuing a film career – in fact he told me this was one of his numerous ambitions when I interviewed him last summer. He has already shot his appearance as Flash Harry in the St Trinians remake and stars in the American romantic comedy Forgetting Sarah Marshall.

All of this is fine and dandy and Brand did spend a bit of time at drama school before dropping out, so acting clearly courses through his once heroin-clogged veins, but I do wish great comedians would stick to stand-up. Eddie Izzard's determination to crack Hollywood has put the mockers on his stand-up career. He seems to have finally made a breakthrough in the TV drama The Riches and his grandstanding cameo in Across The Universe is the best thing in a terrible film, but onstage he has never recaptured his glories of the mid-nineties and I think this is partly due to spending too much time getting onscreen.

Stand-up comedy is like a muscle which needs constant flexing and exercise. Izzard has shown that it is definitely not like riding a bicycle – however brilliant you are, if you take a break you can't just get on again. Brand should bear this in mind. Do a bit of acting by all means Russell, but keep gigging as much as you possibly can or you'll find that your mighty gag-generating mojo might get rusty. And we wouldn't want that, would we?