Extra Cinema: Riot Club (15)

The class war degenerates into foul-mouthed tirades and stomach-churning violence in Laura Wade’s robust adaptation of her own coruscating stage play.

Posh originated at the Royal Court Theatre in London in 2010 and was revived two years later in the West End, painting a vivid portrait of a fictional dining clique akin to the Bullingdon Club at Oxford University, which once included David Cameron, George Osborne and Boris Johnson.

Lone Scherfig’s film, retitled The Riot Club, packs a similar emotional wallop to its stage-bound predecessor .

Alistair Ryle (Sam Claflin) arrives at Oxford, hoping to emulate his older brother, a former president of the titular fraternity.

This hush-hush 10-strong dining club honours the memory of its libidinous 18th century founder by boozing to excess at an annual dinner, trashing the venue and paying for the damages out of their trust funds.

The Riot Club is a sobering attack on a culture of inherited privilege and power in Britain. Scherfig’s film dissects how our society is founded on secret handshakes in wood-panelled rooms far from the madding electorate.

The Danish filmmaker, doesn’t spare the morally repugnant characters blushes.

A climactic showdown is just as jaw-dropping in lurid close-up as it was from the distance in the theatre.

Rating: 7/10