Kit Harington. Picture: Bang Showbiz

British star Kit Harington has slammed Marvel for its lack of gay actors.

The 31-year-old star - who is best-known for his role in 'Game of Thrones' - has called on the studio to take a lead on the issue of diversity.

He told Variety: "There's a big problem with masculinity and homosexuality that they can't somehow go hand in hand.

"That we can't have someone in a Marvel movie who's gay in real life and plays some superhero. I mean, when is that going to happen?"

Earlier this year, Marvel boss Kevin Feige revealed that the studio is already developing an LGBTQI+ character.

Asked whether the character will be someone audiences are already familiar with or not, Kevin replied: "Both ones you've seen and ones you haven't seen."

Meanwhile, Dave Bautista has threatened to quit 'Guardians of the Galaxy' unless Marvel promises to use James Gunn's script.

The director was fired by Disney earlier this year when some controversial tweets, which he posted over 10 years ago, resurfaced online - but Dave is adamant he won't do another film for the studio unless it agrees to use his script.

He said: "James is one of the kindest, most decent people I've met. He's already turned the script for 'Guardians of the Galaxy Vol. 3' and where I'm at right now is that if [Marvel] don't use that script then I'm going to ask them to release me from my contract - cut me out or recast me because I'd be doing James a disservice if I didn't."