Veteran French film-maker Claude Lanzmann is holding a once-in-a-lifetime marathon screening of his nine-and-a-half-hour Holocaust documentary Shoah in Bloomsbury on Saturday.

Michael Stewart, of Richborough Road, West Hampstead, invited Mr Lanzmann to London for his new Open City London Documentary Festival.

The screening marks the 25th anniversary of the documentary which forced its audience to reimagine the Holocaust. Its 86-year-old director will introduce the film and take part in a Q&A session.

Mr Stewart said: “This is one of the greatest films ever made and it will be amazing to see it in the presence of this towering genius. He spent years of his life, largely unfunded, finding survivors to tell this story.

“As well as creating this amazing film, he is an extraordinary man in his own right. He was part of the resistance and fought in the Auvergne. He was Simone de Beauvoir’s lover and, in the 50s, he stood up against the war in Algeria, causing him much hatred in Paris.

“He has never bent to the whims of fashion and Shoah shows that. It is very rare that someone can say that a film genuinely changes the way you view the world. But it is true of this film. You look at people differently, you look at events differently, after you see it.”

Open City is a four-day film festival with four screens. There are 10,000 tickets on offer, all priced at �5 (except Shoah which is �35.) Eleven jurors, including Simon Chin, producer of Man On Wire, Eddie Berg, artistic director of the British Film Institute, and Pawel Pawlikowski, the Bafta Award-winning film-maker and academic will hand out prizes to films across a range of genres.

For those after a cheap movie and a bit of a workout, the �1 cycle-powered outdoor cinema may also appeal. Meanwhile, the pop-up burger company Meatwagon will be bringing its celebrated gourmet fast food to north London from Peckham.

n The Open City London Documentary Festival begins today and is based in Malet Place. For details of film times and booking, visit www.opencitylondon.com.