How To Talk To Girls At Parties is released in UK cinemas on May 11

“It’s a mixture of cultures and subcultures. Both the aliens and punks are tribes on the fringe in the normal grey 70s world of Croydon. “Neil Gaiman was almost signed to a punk band in 1977 and always wondered what might have happened. In a way this was re-claiming the punk youth I never had and the punk stardom that Neil almost had.”

The film continues a renegade aesthetic that appears in much of Mitchell’s work, from his films Hedwig to Shortbus and even his acting appearances in Girls and The Good Fight.

“In everything I do I try to keep in the spirit of do-it-your- self, don’t fit in too hard, but also bring in the audience,” he says. “I always want my films to be entertaining with other stuff underneath, other themes that you might not expect in a romance like this.

“This is by no means a reconstruction of any punk history. This is a punk fairy tale, a teenage romance with an unexpected Brexit theme.”

Mitchell is convinced that punk could play a role in healing social divides in the modern world.

“I usually like to originate material myself, but there was something about this,” he says.

“It draws on Neil Gaiman’s youth as a punk in Croydon and in some ways we need a punk spirit more now than perhaps we did in the ‘70s because of a feeling of darkness, harshness and doom that’s suffusing everyone now.

“In the film there is an unexpected discussion of what punk could be in a healthy way for society now which is very much scared of the outsider and frightened about the future.

“That was certainly happening in the ‘70s here and in the US, which is where punk came from, and I think there does need to be a new kind of punk to answer it, which is different from people screaming on social media.

“That’s not punk, that is actually just screaming, and anger is not necessarily productive if it’s just trying to tear down or trying to make you not pure enough.

“The danger that punk had was it became conformist very quickly — if you’re not this, you’re not punk.

“That kind of reminds me of the PC police now. You can’t use certain words, otherwise you’re anathema or insensitive, so you end up with allies tearing each other apart which happened a bit during the late ‘70s too.”