“What proof do we have that the Holocaust happened?” asks historian David Irving (Timothy Spall) in one of the opening scenes of Denial.

Once Irving brings an action for libel against American academic Rachel Weisz (Deborah Lipstadt) for accusing him of denying the Holocaust and, not to mince words, lying, the questions start coming thick and fast. Big questions. Questions about the nature of truth; the distinction between fact and opinion and the limits of free speech.

Weisz has a few questions of her own. Why does the British legal system oblige her to prove her innocence?  Why is she not going to be called as a witness in her own defence? Why are no Holocaust survivors going to be asked to testify?

Although courtroom scenes, using transcripts of the original 1996 proceedings, are at the heart of Denial, it’s not really a courtroom drama.

The real drama is in the tension between Weisz and members of her legal team who argue that the case is not about proving that the Holocaust happened or that Irving is simply a bad historian, but that he’s a politically and racially motivated liar. Preparation is everything – Barrister Richard Rampton’s systematic dismantling of Irving’s character and credibility in court is only as good as the meticulous analysis of Irving’s books and diaries by a team of researchers and Wilkinson’s own forensic observations in the remains of the gas chambers at Auchwitz.

Denial is a modest and, given its subject matter, understated film which tells a big story and tackles big questions. Not a word of the tightly-crafted script is wasted. Timothy Spall, Deborah Lipstadt, Tom Wilkinson (as Rampton) and Andrew Scott (as solicitor Anthony Julius) all turn in superb performances. Despite Weisz’s courtroom victory, Denial will leave many filmgoers with a sense of unease and prompt them to asking disturbing questions of their own.

Don’t miss.