OUR BRAND IS CRISIS (15) 107 mins. Starring Sandra Bullock, Billy Bob Thornton, Anthony Mackie, and Joaquim de Almeida.

COLD, unvarnished truth rarely darkens the doorstep of modern politics.

Instead, slick sound bites, unsustainable promises, smear campaigns and scare tactics are employed to herd an apathetic electorate, which gets more excited about the winner of a reality TV contest than the shifting sands of Westminster.

Our Brand Is Crisis is a sharp and sporadically biting satire of political spin and intrigue, inspired by Rachel Boynton's 2005 documentary of the same title about the impact of American campaign strategists on the outcome of the 2002 Bolivian presidential election.

David Gordon Green's film retains the South American setting, but blurs the line between art and life with fictional characters on both sides of the social and political divide.

Scriptwriter Peter Straughan, who penned the 2011 version of Tinker Tailor Soldier Spy, arms his morally corrupt characters with an arsenal of polished one-liners to justify their underhand tactics.

Sandra Bullock and Billy Bob Thornton are a delicious double act at the centre of these machinations, playing rival spin doctors who will stop at nothing to undermine each other's candidates.

Even the campaign bus rides along winding mountainside roads turn into a potentially fatal game of chicken between the two camps.

Our Brand Is Crisis hinges on Bullock and she displays impeccable comic timing, whether it's physical pratfalls like falling down airplane landing steps or tossing verbal grenades at everyone in her eyeline.

Thornton is a lip-smacking foil and the actors relish heated exchanges in Straughan's script.

The film loses its way in a final act that tugs heartstrings and ignores everything that Jane professes about the mucky business of electioneering.