The $20-million war epic Passchendaele by writer/director Paul Gross will open the Toronto International Film Festival in September, organizers announced on Tuesday, putting a film already known for its big budget and intended mass appeal in a slot that has recently favored arty and less-accessible fare.

‘This is one you really couldn’t ignore,’ festival co-director Cameron Bailey tells Playback Daily, adding that organizers were ‘swept away’ when they saw the unfinished film, currently in post-production. The Alberta-shot drama is the most expensive movie ever made that was funded solely in Canada, according to Telefilm Canada.

It follows the 1917 battle for the titular Belgian town during World War One, in which Canadian, British and Australian troops fought the Germans under atrocious conditions. Gross based the story on the experiences of his grandfather, who fought in the war, and stars alongside Caroline Dhavernas (Surviving My Mother, Wonderfalls) and Gil Bellows (Ally McBeal).

The film is produced by Niv Fichman of Toronto’s Rhombus Media, while Gross and Frank Siracusa of Whizbang Films, and Frances Damberger of Calgary’s Damberger Film and Cattle Company serve as coproducers.

Bailey says organizers were looking for something that ‘reflected Canadian film culture’ and that would fill the screen, as it were, at Roy Thomson Hall, home of the festival’s gala screenings. The opening films at TIFF have recently been smaller-scale and less commercial, such as last year’s literary reworking Fugitive Pieces and, before that, the glacially paced The Journals of Knud Rasmussen.

Passchendaele, on the other hand, is being billed as a come-one, come-all war story complete with action and romance.

Bailey adds that there was also buzz around the project because it shot in Alberta. ‘It’s a part of the country that doesn’t usually make this scale of a film,’ he says.

TIFF won’t say which other films were in the running for the top spot, though the contenders would presumably have included Atom Egoyan’s Adoration and the Fichman-produced Blindness, both of which played last month at Cannes. Bailey also notes organizers have seen some ‘really good stuff’ from Quebec this year, both from veteran and new filmmakers.

The 33rd Toronto film fest runs Sept. 4-13. Passchendaele will be released in theaters through Alliance Films on Oct. 10.