It was 2001 when Joe Cornish first conceived Attack the Block, in what seem like fairly unlikely circumstances for inspiration: he was being mugged by a gang of young kids. In fact, the same scene opens the film itself, which has finally leapt onto the silver screen after ten years of gestation and hard work. When I sit down to chat with Cornish, I’m sceptical that his first thought when having his wallet taken was, ‘Ooh, this’ll make a good film…’, but he laughs at this. ‘Oh no, that’s my first reaction to everything that happens to me. I’ve wanted to make a film since I was a kid, and my head’s been full of films since I was about seven. I’m afraid I’m one of those people who looks at everything and thinks about how it would play as a film.’

Although inspiration may have come from a somewhat unconventional source, the result is stunning. The plot is both simple and outlandish: a group of kids are midway through mugging a young woman, when they are interrupted by an alien invasion, and they spend the rest of the film defending their tower block from the extra-terrestrial threat. Although largely made up of unfamiliar faces, the young cast are brilliantly convincing, inhabiting a film that’s far more thrilling and cinematic than people might expect.

Attack the Block is one of the most original and stylish debuts of a British writer/director in years. This might surprise those familiar with Joe’s prior career as one half of comedy duo Adam and Joe, where the only hint of his cinematic future was the cuddly toy film re-enactments they used to make for their TV show. Despite the lack of cuddly toys here, Attack the Block looks like the work of a supremely confident and film-literate mind. Yet given its abundance of action and special effects, Cornish didn’t give himself the easiest first gig: had he always intended to direct it himself?

‘Yeah, absolutely. Always intended to. I’ve always wanted to direct, and particularly on this because I felt that would be the way that I would know exactly what was going on in the script, and be totally confident that I understood all the elements of the story, and I wouldn’t end up fucking up someone else’s masterpiece.’ So did he feel confident in steering it towards the screen? ‘No, it was surprising. To be honest, I had no idea. I’m one these people that for years has enjoyed film-going like sport. But when you actually make one, you realise what an incredible endeavour it is just to make anything coherent , and you realise the genuine amount of hard work involved. It annihilates all your personal relationships and your weekends and your holidays – it’s 24 hours a day for years, literally. But I loved it, I thought it was incredibly good fun.’

Still, Cornish isn’t quite new to this game. Over the past few years, he’s secretly been making a name for himself in Hollywood, co-writing the upcoming Tintin and Ant-Man while rubbing shoulders with, amongst others, Stephen Spielberg and Peter Jackson. I suggest that hanging around with such experts seems to have paid off, but Joe hesitates at this. ‘Riiight. Well, that’s nice of you to say, but those were both writing gigs. Ant-Man I’ve been working on for a while with [Shaun of the Dead director] Edgar Wright, and being friends with him has been a huge boon to me, because he’s taught me a huge amount, and tolerated me hanging around, watching how he does things.’ As a result of this association (Wright executive-produced Attack the Block), as well as due to its niche genre of horror-comedy, I remind Cornish that there have been an abundance of pretty lazy comparisons to Shaun of the Dead by both reviewers and the film’s marketing team.

‘Sure. I think it’s a very different film. I think Edgar’s a genius and I would be an idiot to try and do something similar. I think mine is more like a John Carpenter film. It’s less funny than Shaun of the Dead, it isn’t intended to be as joke driven. It wants to be a little more real, and maybe with a tiny bit more social commentary.’ Apart from anything, the setting is a very different one; while Shaun seemed fairly closely modelled on Wright and Simon Pegg’s own lives (give or take a few flesh-eating zombies), Attack the Block must be far less familiar territory for Wright, with its young cast and their distinctive inner-city slang. I suggest to Cornish that it wouldn’t necessarily be the first setting that people might associate with him, but he riles at this.

‘No, with great respect I think that’s a very reductive attitude. If you go through art and culture and eliminate everything that isn’t based on the author’s first hand personal experience, you’d lose the vast majority of it. So I wouldn’t even begin to think about it like that. I think that’s reductive and not the way to look at things, really.’ Feeling thoroughly scolded, and surprised by the irritation in Joe’s voice, I guess that I’m not the first to ask such a question. In fact, it’s understandable, given the work he put into immersing himself in that world. ‘The script was evolved from months and months of workshops with youth groups around south London, in which I interviewed them and talked them through the story. I recorded and transcribed personally everything they said and I taught myself the language they spoke, as if it was a foreign language. We worked extremely hard to create an authentic argot or slang, but we’ve also kept it quite simple and accessible.’

As the interview draws to a close, I feel obliged to ask about the future of The Adam and Joe Show on BBC 6Music. Even if Joe does become a big-shot director, will he continue to chat entertaining rubbish with Adam on Saturday mornings? He chuckles at this. ‘I hope so. I think what we’ll probably try and do is do little runs every now and then, if someone will have us. I think it’s quite healthy for both of us to do something outside of the radio show, and I don’t think either of us necessarily wants to spend the rest of our lives doing that show… But I came straight back from shooting, straight back onto the radio – I didn’t even have a day off, and that’s an expression of how much I love doing that show and how much I feel I owe the audience.’ Some fans might be a little disappointed by Adam’s absence from this film (if you discount his brief aural cameo, narrating a moth documentary on TV in one scene). Did Joe not want to give his professional other half a starring role? He laughs. ‘He’s my best friend in the world, and very talented, and as such, for my first film I wanted to be careful. If I fucked it up, I didn’t want to take him down with me.’

So after twenty-five years of looking at everything in the world and thinking about how anything might make a film (even a mugging), did he treat this as his one chance to shine? ‘Kind of. I didn’t sort of throw everything in like someone on a ridiculous trolley dash. But I have been waiting to do it for a long time and I’m acutely aware that the British film industry has a huge list of first time directors, a smaller list of second time directors, and a very small list of third time and career directors. I knew I had one shot. I wanted to do something ambitious, so that if it succeeded it would be exciting and if it failed it would be a heroic failure.’ In fact, it’s neither. And Joe certainly hasn’t ‘fucked it up’. Instead, Attack the Block is a fiercely original action flick that, along with similarly brilliant debuts like Moon and Submarine, represents a new wave of young British filmmaking talent. Being mugged can really pay off.