What a time to do a political show. As election loons, we have a moribund, unpopular government fighting unwinnable wars, bailed-out bankers still revelling in obscene bonuses, the unpalatable rise of the far right bigots, and a bunch of self-serving MPs with their snouts in the gold-plated trough that they no doubt claimed on their ridiculously lax expenses. For a political comic, there’s a lot to get bitterly angry about.

Not, though, The Black Sheep – aka Ciaran Murtagh and Andrew Jones – with a cosy, unashamedly old-fashioned satirical revue with a political content so vapid it has all the bite of a toothless crone with gingivitis.

Politicians never answer questions, ‘three-line whip’ – sounds a bit kinky, Margaret Thatcher was a bit like aman; These are the starting point for some of their gags that are as weak as Gordon Brown’s poll ratings. And those are the most politicised scenes – plenty have no on-topic raison d’etre at all.

One typically toothless skit has Thatcher singing new lyrics to Queen’s Don’t Stop Me Know – an idea that have been would have been too weak to make it onto Spitting Image when she was in power, so a decade after she left Downing Street makes for a rather pointless exercise. Another weak musical number sets Martin Luther King’s I Have A Dream speech to the Abba song of the same title.

Not everything in comedy needs a hard-hitting agenda, of course, but when you choose an area such as politics which is – alongside sex, drugs and religion – one of the cornerstones of life, let alone comedy, you would hope for something that aimed higher, or at least came from a different direction.

With no particular agenda, this can only be a couple of hours of empty frippery. Luckily, the saving grave of this show is that both Murtagh and Jones are talented, confident performers, ably to inject a dose of class into even the most ailing material. So as empty frippery goes, it’s all very well done (all that is, except for a Karl Marx version of Go West, which is uncharacteristically under-rehearsed).

You can also see the steady hand of acclaimed comedy director Cal McCrystal at work. There’s an inventive wood-panelled set, evocative use of background music and set performances pieces such as the old improv game where each player says alternate words in a sentence, a near-silent slapstick and a spoof paper-tearing that provide lots of good-natured spirit. The downbeat monologues of invented childhood reminisces that each actor performs is especially powerful in showcasing their talent at manipulating that mood, but again adds nothing to the comedy quotient.

The double-act banter is clearly scripted, but they avoid making it too forced and they are especially accomplished when engaging with audience for the sake of a silly poll that opens the second half. Other highlights include Jones’s fantastic comedy turn as a breathless EL Wisty-type constituent, speaking so non-stop you’d think he was on cocaine.

They can take subjects from the headlines – this show contained a sketch about Professor David Nutt’s sacking as a government drug adviser – but the style is undeniably dated, from the parade of corny knock-knock that owes its presentation to Rowan and Martin’s Laugh In to the obligatorily jaunty closing number ‘Vote For Me!’

In one wry sketch they make the point that political cartoons don’t have to be funny – which is certainly The Black Sheep calling the kettle black; there’s little here that would pass muster on Have I Got News For You? or the countless other topical TV and radio comedy shows, despite the charm of the stars and their gift for absurd performance. Give me the The Thick Of It over this any day.