The long-running British sitcom Red Dwarf should be held up as “a bastion of diversity in television”, one of its stars has said.

Speaking to the Radio Times to promote a feature-length episode of the show, to be aired 32 years after the series debuted, Danny John-Jules, who plays Cat, said the comedy’s unique format and diverse casting was “totally ahead of its time”.

“All this rubbish they’re talking about diversity today makes me laugh through my teeth,” he said. “Fifty per cent of its cast were black, you never had a person’s colour mentioned once – 32 years later and we’re still doing that.”

The show is set aboard the eponymous Red Dwarf spaceship in 3m years’ time, and tells the story of Dave Lister, the last human alive, played by Craig Charles. He is joined by Cat, the hologram Rimmer, played by Chris Barrie, and Kryten, a mechanoid played by Robert Llewellyn.

Red Dwarf was broadcast by the BBC from 1988 until 1999, when it was put on hold to prioritise new projects. It was revived a decade later by the digital channel Dave, which has since produced a further three series, each one achieving some of the station’s biggest ratings.

The new feature-length episode, The Promised Land, will air on Dave in April.

Rimmer and the Cat face the worst prosecutors in the universe.

Also speaking to the Radio Times, Barrie said the show had always been “completely different to anything else on television”. Llewellyn said: “It’s a science-fiction sitcom where the comedy isn’t about the science fiction.”

Red Dwarf’s first six series were written by Rob Grant and Doug Naylor, with the latter writing series seven to 12 either alone or in collaboration with other writers. Naylor had planned for years to also make a big-budget Red Dwarf film but funding for the project fell through.

Despite the extended running time, bigger sets and improved special effects, Naylor said the feature-length episode was not the Red Dwarf film. “That [the movie] had a budget of £20m. The special is a 90-minute story and has a very handsome sitcom budget, but it’s nothing like that.”

Naylor said he would be “stunned” if Dave’s owner, UKTV, did not commission more scripts, adding that the cast were as enthusiastic as ever to return for further episodes.

“I’ll keep making them as long as people want to watch them and we’re having fun,” Charles said. “I think I’d be sad the day I realised Red Dwarf had become a thing of the past.”