Man Down is on tonight - make sure you watch it!

You know what I mean, don’t you? That feeling of slight trepidation just before you’re about to watch the first episode of a British scripted comedy?

They are said to be the hardest thing to get away in TV terms, and it often shows.

In fact I can’t think of a new show originated on this side of the pond I haven’t been mildly disappointed by for quite a while.The Wright Way was dire, Chickens wasn't half as funny as it should have been and Family Tree was intensely disappointing.

But this time things were quite different and the show, Channel 4’s Man Down, which C4 showed at a preview screening was… a joy.

It stars Greg Davies – best known as The Inbetweeners' irascible head of sixth form – as another teacher, Dan, whose haplessness is high tungsten, if not nuclear. He cannot even manage to wear a pair of trousers to his workplace, a secondary school where he teaches drama. We say teaches, but mucks around is more like it. And mucking about is something Davies is exceptionally good at, deploying the full range of his enormous physicality (believe me, I met him this week and he is HUGE) alongside the excellent comic timing you'd expect from a seasoned stand-up.

The plot centres around Dan's desperate attempts to win back his girlfriend (Deirdre Mullins). That he is unsuccessful is probably down to the fact that his strategy involves being silly (by which I mean really quite exceptionally cretinous) with his sidekicks – a fabulously weird duo played by Roisin Conaty and Mike Wozniak.

The scene in which Davies and Conaty perform a salsa dance in a hospital had me close to falling on the floor with laughter.

There is also the mad intervention of Davies' Dad, played by Rik Mayall, who not only bears a weirdly striking resemblance to his on-screen son, but produces a madly violent, bulgy-eyed cameo of hilarious punch and gusto.

But Davies – himself an unhappy drama teacher until he quit in 2004 – is the absolute star, playing the role with unbridled brio in a project where Channel 4's execs seem very wisely to have steered away from interfering (the result being, I gather, that they are very pleased with it down Horseferry Road).

And of course, while it seems anarchic, the clever thing is it is very tightly plotted.

“I hope it came across in filming that we had a blast,” Davies said at the launch.

You bet it did.

Man Down airs on Channel 4 on 18 October

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