Coalition

Its plot is by no means fanciful. Matt Cooper (Thom Tuck), a thinly disguised Nick Clegg, presides over a disintegrating party which is riven by division and tainted by supine complicity with failing Tory policies.

In a desperate bid to redeem his authority he provokes a split by backing the expansion of nuclear power and thus forcing the resignation of his energy secretary Geoffrey Webb (Alastair Barrie).

This backfires when Webb resigns his seat and in the subsequent by-election defeats the Cooper-sponsored Lib Dem candidate.

In a final throw of the dice Cooper resigns, hoping to re-establish his credibility through a leadership contest. But the Prime Minister calls an early general election, leaving the Lib Dems leaderless and flailing. In this game of "coalition chess" it's checkmate to the Tories.

The play is certainly an excoriating glimpse into the dismal chaos that is the Lib Dems' contribution to coalition government and it's at its most acute in the exchange between Cooper and Webb when it becomes apparent that political principles are easily trumped by personal vanities and political pragmatism.

The play's focus is almost solely on the Lib Dems, largely depicted as a bunch of talentless and self-serving incompetents with Webb and the Chief Whip Angela Hornbury, played with calm and assured insouciance by the excellent Jo Caulfield, the exceptions.

The biggest curtain call is claimed by Phil Jupitus who camps it up outrageously as the scene-stealing Tory Minister without Portfolio Sir Francis Whitford, whom he portrays as a manic hybrid of Eric Pickles and John Inman. Perhaps he needs to realise that sometimes less is more, as evidenced in the scenes he shares with Caulfield. Thom Tuck bears a passing resemblance to Clegg but again tends to overdo the histrionics.

That diminishes the effectiveness of what could have been a telling satire on coalition politics and political chicanery and, as a result, this is more pantomime than comic satire.

Runs until March 10. Box office: (020) 7609-1800.