The comedian’s new film imagines a future where everyone is vegan…

Consider a future where eating meat is illegal and everyone is vegan. This is Britain in 2067, as imagined by comedian Simon Amstell in his new satire film Carnage: Swallowing the Past.

Young generations look back with disgust at the eating habits of their grandparents and elderly people need therapy to come to terms with the crimes they committed against animals in their past.

Featuring real and imagined archive footage from past, present and a utopian future, the film doesn’t pull any punches and even features a scene where Absolutely Fabulous star Joanna Lumley plays a goat who asks: “Why do you keep making me ejaculate?”

“The first person who came on board was Joanna Lumley,” Simon said. “The producer had her email address and said ‘Just email her’. This was right at the beginning, the script was an early draft, it had kind of been commissioned but I still wasn’t sure if it would actually happen. But Joanna wrote back saying. ‘Of course I’ll do it darling’. As soon as she agreed to say that line the whole became quite real!”

Simon couldn’t believe his luck when it came to the casting process and a stellar line up of cameo performers also includes Sherlock’s Martin Freeman and Bridget Jones’ Diary star Gemma Jones.

The comedian, who has been a vegan since a trip to Thailand during his 20s, decided not to browbeat his talented cast on the evils of being ‘carnists’, a term he coins in his film.

“If everyone on this project was a vegan then I would have been very lonely,” Simon explained. “I wanted it to be good so if Martin Freeman was going to be in it, I wasn’t going to tell him he mustn’t eat pork. Eat whatever you want as long as you say these words well!’

Amstell, who enjoyed a long stint as presenter of TV music quiz, Never Mind The Buzzcocks,  said he wanted to make a documentary about veganism that would raise some important points while also making people laugh.

“I thought it would be a good idea to make something funny,” he said. “I wanted to put the message across in a way that didn’t traumatise people. I’m not an activist – I’m a clown. I was going for funny.”

Carnage doesn’t pull any punches in its depiction of a food industry that “rapes cows for milk”, yet despite the vivid imagery, there were a few scenes that didn’t make the final cut for legal reasons.

“We had an idea for a war crime tribunal,” said the comedian. “Putting people in prison from the past, like Jamie Oliver. But thankfully, someone at the iPlayer thought that was not a good idea!”

Carnage: Swallowing the Past comes exclusively to the BBC iPlayer on Sunday 19 March.