Did President George W Bush pull strings to gain a cosy billet as a pilot in the Texas Air National Guard from 1968 to 1974, thereby dodging combat in Vietnam? And did he subsequently go AWOL from the Guard before his term of duty was up?

CBS news producer Mary Mapes was trying to ask these highly contentious questions on the eve of the 2004 presidential election and came under blistering fire from right-wing politicians and bloggers in return. The outcome wasn’t pretty, as Truth – writer-director James Vanderbilt’s tense, absorbing, and clear-sighted reconstruction of those events – reveals.

Anchored by a blazing performance by Cate Blanchett as the resolute Mapes and a studiedly cooler one from Robert Redford as legendary US newscaster Dan Rather, Truth delivers a gripping account of the efforts of Mapes and her ’60 Minutes’ news team (played by Elisabeth Moss, Topher Grace and Dennis Quaid) to nail down the veracity of their story, only to find undeniable proof slipping from their grasp as witnesses recant and revelatory documents are denounced as forgeries.

As Blanchett’s combative Mapes discovers to her cost, the American Right is only too happy to make the story in question one of flawed reporting by a ‘liberal, Feminazi, evil lefty sneak’ rather than the issue of the US Commander in Chief’s dubious military record. And, the more controversial the story becomes, the more eager the CBS suits become to protect their corporate interests and cut Mapes and veteran presenter Rather loose.

There’s lots of food for thought in Zodiac screenwriter Vanderbilt’s directorial debut, not least the chilling observation that as soon as the US TV Networks realised they could make money from reporting the news they began creating the media climate of sensationalism and rabid partisanship we live with today.

Certificate 15. Runtime 125 mins. Director James Vanderbilt