Denis Lawson was the first of the new faces to join New Tricks, the BBC’s long-running cop show. Compared to Dennis Waterman, Nicholas Lyndhurst or the man he replaced, James Bolam, Lawson seems to have drifted to the top of the British thespian fraternity without ever landing that defining role.

He doesn’t have to worry about persuading audiences that he’s not Terry McCann, Rodney or Terry Collier in this one. You recognise him, but don’t really associate him with anything other than quality.

He pops up everywhere and his latest role is in a small budget British sci-fi film The Machine – a story about a scientist who is experimenting with artificial intelligence and trying to create a new breed of super soldier for the Ministry of Defence. The ultimate result of his work is a self-aware, artificially intelligent machine, played by Caity Lotz.

I suggest to Lawson that a small budget film set almost entirely in an underground bunker in Wales isn’t the most obviously appealing project, but he says it was easy to say yes to. “It was a very, very good script, really interesting and a nice part, dark and funny at the same time.” It also offered an opportunity to work with Toby Stephens, someone he’d known for a while but never worked with.

Stephens plays the Victor Frankenstein of the piece, a conflicted, driven scientist who plunges into his research without always considering the ethics of what he is doing. He is, though, the hero, while Lawson’s character, Thomson, is very much the baddy, an utterly ruthless base commander concerned only with getting the perfect fighting machine and improving his golf game. Generally, actors playing the villain will claim to have tried to empathise with them, but when I ask if he thinks the film is a little hard on Thomson, he laughs and roars no. He has no sympathy for him: “He’s a minor dictator in his own world. He runs that site and has complete power over everybody. He’s totally corrupted by it … they are all buried in this claustrophobic world where they lose track of their moral sensibility.”

Directed by first-timer Caradog James, the film has a marvellous, oppressive visual sense. It is always raining and everything seems to happen in dark subterranean offices. He is full of praises for the Danish director of photography Nicolai Brüel for his minimalist lighting style. “It’s always exciting as an actor to work in interesting light. There was very little light on set so, in one scene, it was done with Caity Lotz and just a reading lamp on the floor.”

It was mostly made in a huge aircraft hangar outside Cardiff and an industrial estate – not the most glamorous location but apparently not too uncomfortable. According to Lawson, the only time the reality on set was as bad as it looked on screen was when they were doing some pick-up shots some months after the initial shoot, under a waterworks in Surrey “which was ghastly, cold and damp and miserable, really uncomfortable”.

This is likely to be a one-off incursion into sci-fi, unless there is a Local Hero reunion with Peter Capaldi on Doctor Who. Asked if there would be family representation in the upcoming Star Wars trilogy – Lawson played fighter pilot Wedge in the first (or now middle) three films while his nephew Ewan McGregor was Obi Wan in the prequels – he reveals that Star Wars now “bores me to death”.

Running workshops

Of much more interest is his next project, the publication in the summer of a book for actors about working on camera. Over a 20-year period, he has been running workshops for working actors and drama students, preparing them for the demands of the screen. Though “drama schools give you a brilliant training for the stage, absolutely brilliant, and they do do a certain amount on film work and they’re getting better”, he is constantly meeting young actors who are disorientated by the medium. “The experience of working on a film set is completely different from working on a stage, surrounded by people and not knowing who’s doing what and why. It’s acting at 7.30 in the morning rather than 7.30 in the evening.”

The Machine is in cinemas/VOD on March 21 and out on DVD/Blu-ray on March 31. www.themachinemovie.com.