Chewing Gum star Michaela Coel experienced 'racist attack' while filming The Aliens in Bulgaria

So it is perhaps grimly ironic that Coel herself suffered what she believes was a racist attack while she was filming scenes for the drama in Bulgaria late last year.

“I was coming out of the supermarket with [fellow Aliens actor] Reuben Johnson…and we were just walking home and we started feeling stones around our ankles and we turned around and there were just four Bulgarian guys stoning us,” the 25-year-old tells RadioTimes.com.

The incident was grimly reminiscent of a similar event which took place in her native London a few months before. Coel and actor Kobna Holdbrook-Smith (Laertes to Benedict Cumberbatch’s Hamlet in the recent stage production) were minding their own business in Hoxton east London – only to find themselves pelted with stones from some people in flats above them, Coel says.

“It shows there’s also a side of racism here [in the UK] as well,” she adds, adding that neither experience put her off her stride. After all, the incident in Bulgaria happened on a very special day when she was in the mood for celebrating.

“To be honest it was my birthday, I was having a party so I went back and partied. What am I gonna do, spend the next three months crying about it? I’ve got a job to do, you know there are pathetic sad people everywhere, here too, that don’t have a lot going on so that’s the way they’ve chosen to feel because it gives them a focus. No, it’s my birthday, mate, I’m having a party.

“For every one of those rotten apples there’s a hundred lovely ones. I met so many lovely Bulgarians… it was a completely isolated incident.”

Equity, the actors’ union, remains extremely vigilant about incidents like these but a spokesman said that in recent years it has not received any complaints of the kind outlined by Coel. The spokesman added: “Racism of any kind – let alone the extreme harassment experienced by Michaela in Bulgaria – is completely unacceptable and any Equity member who experiences racism at work should contact their union which will take action immediately.”

For her part, Coel refused to allow the incident to spoil her enjoyment of filming – or the pleasure of the finished series, which she says manages to blend a fantasy realm “bang in the middle between the world we live in”.

The drama speaks about urgent contemporary concerns, she adds. The ghettoisation of the aliens is not just about skin colour, she believes, speaking as it does of modern anxieties like people who are being priced out of places like central London and forced to move to the fringes of their city.

It is also, she is happy to say, science fiction that is “not just a bunch of posh people, fighting demons”. This apparent barb against a hugely lucrative film genre (think films like Twilight and maybe even Harry Potter) feels like the kind of remark that could have been mouthed by one of the more outrageous characters from Chewing Gum, E4’s sleeper comedy hit of last year which Coel wrote and starred in.

This rip-roaring series took us into the world of Coel’s Tracey Gordon a 24-year-old virgin awakening to her burgeoning sexuality in a strictly religious household in a tough London estate.

Based on her 2012 National Theatre play Chewing Gum Dreams the comedy was semi-autobiographical. Coel herself was in reality once a teenage Christian convert herself – bringing the rest of the family into the fold (they remain believers, but she isn’t any more).

“I did five years,” she says making it sound a bit like a prison sentence, adding that she lost most of her friends because she kept telling them they were going to hell.

Little wonder then that she admits to being “an extreme sort of person”. But fortunately for TV viewers that boundless energy is now being funnelled into her TV work and she is currently working hard on series two of Chewing Gum which is scheduled to return at the end of this year.

“I've storylined it and written episode one of the new series so we're getting there. Honestly, you get very scared before a show comes out, and you do all that 'Oh no, people aren’t going to like it' blah blah. But I was really pleasantly surprised and happy that there was so many more people in favour of the show than not in favour of the show.

"But also I know that if I do it and it’s not good I’ll be prepared for not so positive feedback. So I’m not going to hold onto it and let it give me some kind of confidence because I know that the minute I write something crap, I’ll be hung for it. It was lovely, really just the people in the street that you meet and say how much they liked it... Yeah it’s lovely."

One of the joys of Chewing Gum was that it described and evoked the London Coel knew and knows.

"If I want it to achieve one thing it is for people who, if they see a rude girl like you got on that [Chewing Gum] estate, I want people to think, could I have a coffee with her, maybe she's a bit quirky...? If you approach something differently like that, life is so much better.”

It’s a lesson she exemplifies perfectly. And one those Bulgarian and Hoxton stone throwers would do well to heed as well.

The Aliens starts on E4 on Tuesday 8th March at 9pm