David Edgar is a consummate master of scenarios. His characters debate nuances of wording, unroll assorted sequences of whataboutery and somehow almost always manage to make the consequences luminously human rather than aridly theoretical, even when the debate is between 17th-century theologians about determining the text of the King James Bible as in his Written On The Heart for the RSC last year. He is also unabashedly politically engaged, which can make him seem something of a dinosaur, as in the case of the unjustly maligned Playing With Fire in 2005. In If Only, both these strains are well to the fore. It would be easy to dismiss much of it as old-leftie wish-fulfilment. Easy, and dead wrong.
    
The first act takes place in April 2010. A Conservative, a Liberal Democrat and a Labourite, each reckoned a coming power within their party, are stranded in Europe by the Icelandic ash cloud and trying together to get back to Britain to resume their roles in the current election campaign. As they travel, they speculate on possible electoral outcomes, in particular the alignment of the Lib Dems in a hung parliament. There is much scope for satire involving 20/20 hindsight, and it is even plausible that such “war-gaming” could have taken place, although the idea of a tripartite conspiracy to shape the eventual consequences is somewhat fantastical.
    
But this is all a sucker punch for the second act, set in the near future on the centenary of the outbreak of World War One, when the trio must decide what to do with their knowledge in the face of a rightward-lurching government. These scenarios, too, are terrifyingly plausible; such hope as Edgar may evidence is inextricably grappling with a tar-baby of desperation.
    
This is not a perfect play: the fourth character is too obviously a holy fool in the first act and a convenient ogre in the second. Jamie Glover may be a little too mannered in Act One as Peter the Tory. But it trenchantly identifies a looming threat in the British polity as a whole, and Angus Jackson’s production keeps the pulse beating in both the characters and our common citizenship. It is almost exactly everything that one thinks of Chichester as not being, even under the current astute management. But it is riveting, and it is important that it be seen.

Written for the Financial Times.