The Centurion director told Empire that his feature will bring the '70s show, about cops William Bodie (Lewis Collins) and Ray Doyle (Martin Shaw) and their exploits for CI5, into the present day.
"It's going to be a hard-hitting action movie," he said. "I always loved the show. It has one of the greatest theme tunes ever and a really great central premise. I just thought, 'This is going to make a great movie'."
He continued: "They deal with anti-terrorism, assassinations, political intrigue. The slogan, or kind of the tagline for the film, is 'Fight fire with fire' and that was their whole thing... Primarily it's going to be an exciting movie, but there's an inherent political angle on the story."
Marshall likened his Professionals film to American movies Lethal Weapon and Butch Cassidy And The Sundance Kid.
Marsall is also working on horror project Burst 3D with Sam Raimi.
> Click here to watch our interview with Neil Marshall