The star, real name Ben Ballance-Drew, will play Detective Sergeant George Carter in the film opposite Ray Winstone's Detective Inspector Jack Regan - characters first played by Dennis Waterman and the late John Thaw on U.K. TV in the 1970s.
Due to touring the U.S. with fellow Brit Adele and trying to juggle numerous projects, Ballance-Drew admits he's been forcing the movie to fall behind schedule.
He tells the BBC, "As soon as I've finished touring in America with Adele I'm going to finish my film, finish my next album and start work on The Sweeney in November. I'm kind of holding it up."
But the star insists he would never rush any of his ventures, because he's too much of a perfectionist.
He adds, "It's so important that I get the things I need to get finished completed and to the right quality. I could rush it out and say it's finished but I can't stand doing that. If I'm going to be 100 per cent up there (on stage) my mind has to be on that."