Moses is TV manna

In the same week that the "new" revamped Minder hits our TV screens, with its cosily familiar London support cast of black cabs, white cockneys and East End pubs, a rather more interesting new drama begins on BBC2, portraying a very different sort of 21st-century London.

This is the vibrant, multicultural metropolis peopled with (and largely serviced by) immigrants – legal and otherwise – of all creeds and skin tones, the sorts of people that EastEnders, for example, has struggled to incorporate into its mix. It's the capital as glimpsed on the margins of the mainstream drama – in films like Kidulthood and Adulthood – and issue-driven docu-dramas about knife or race crime. And it is now being powerfully brought to life by Moses Jones – an entertaining and rather violent detective thriller that's also an intriguing sidelong look at aspects of the recent immigrant experience.

The three-part serial follows the eponymous Metropolitan Police inspector (played by Shaun Parkes) of Ugandan heritage, and his fellow officer (played by Matt Smith, recently unveiled as replacing David Tennant as Doctor Who) as they delve into West London's African community. They are trying to find out who has ritually murdered an elderly down-and-out African, packed his body into a suitcase and dumped it into the Thames. In the process they unearth a demi-monde of illegal workers – cab drivers, toilet cleaners, road sweepers and prostitutes – struggling to survive while bending to the will of their community's violent, self-imposed Mr Big.

The serial is the creation of Joe Penhall, who also wrote the television adaptation of The Long Firm, the Jake Arnott novel that brought a gay sensibility to bear on Kray-era London. Penhall has written stage drama before, notably Blue/Orange for the Royal Court (later adapted for BBC4), in which a psychiatric patient claims to be the son of an African dictator, as well as the screenplay for Ian McEwan's Enduring Love. But Moses Jones is his first original TV screenplay.

"We approached Joe after The Long Firm," says executive producer Hilary Salmon, "He said he'd been thinking of doing this idea in the theatre before realising it could actually make a great offbeat TV thriller. He was in Uganda, where he met a lot of people who were around Idi Amin; he had a story in his head about what it would be like to be terrorised by someone like that.

"He's always lived in west London and is very interested in migrant communities. He'd always wanted to know, for example, the guy who runs the cab office – what's his story? And you put those two things together, what if somebody like Idi Amin comes to London and starts terrorising his community again? What choices do they have in a democracy? Will they be defended by the police? And given that some of them are illegal, what rights do they have then?"

Penhall himself says this obsession with African leaders such as Amin and Mobuto (former dictator of Zaire), which first surfaced in his award-winning play Blue/Orange, dates from his childhood. "But whichever era you're in there's always one of them whether its Amin in Uganda or Mobuto in Zaire or Mugabe they follow the African 'big man' blueprint – with his fingers in all the pies and ruling with a combination of fear and magic and charisma."

Mind you, says Penhall, his plot for Moses Jones was pure artistic imagination that turned out to have a basis in reality. "I hooked up with some young Ugandan guys in the East End who are part of the band who appear in the series. They said, and this was a long time after I had written it, 'this is incredible; this is exactly what we go through'.

"There are all these people who were in Milton Obote's army or Idi Amin's army and have washed up over here and they wield this incredible power and influence – and hold people in fear. They call them 'dons', and they still run things: clubs, rackets, brothels, false papers, stuff like that. It was a work of intuition that turned out to be pretty accurate."

If Moses Jones continues some of the themes of Penhall's Royal Court hit Blue/Orange, it also echoes and updates his adaptation of Arnott's The Long Firm, with its depiction of Sixties London's corrupt underbelly ."I loved The Long Firm and I love Jake Arnott's work," he says. " But I wasn't interested in doing Jake's He Kills Coppers [adapted last year for ITV1 by Ed Whitmore]. I really wanted to do my own thing... and I had all this Ugandan and African stuff hanging round and it just seemed to work. The idea was the same as The Long Firm – lots of music, lots of violence, lots of London."

Blessedly free of shots of the gherkin tower or sweeping aerial views of the Thames, this is a gritty, noirishly glamorous city of street markets, neon-lit underpasses, massage parlours and sweaty dives. Parkes, who was in the stage and TV versions of Penhall's Blue/ Orange, takes his first leading role (after many supporting roles in films as diverse as Human Traffic and The Mummy Returns) as the titular hero.

"In Blue/Orange he brought a very lugubrious quality to the part – and I saw Moses Jones like that," says Penhall. Parkes is quick to return the compliment. "I really like Joe's writing and he's one of the top, top writers in this country," he says. "I also like filming in London – it was nice to be able to have a sense of, yes, we are in London; these people are around us. The guy you see sweeping the road or whatever, a lot of these aren't acknowledged in films. Just London life passing you by."

Parkes's police sidekick is an ambitious young detective played by Smith – a serendipitous piece of casting, admits executive producer Hilary Salmon. "We've got the new Doctor Who! We didn't know that when we cast him, but we have. Although obviously we're not particularly aiming at the Doctor Who audience."

The series' only other "name" is Dennis Waterman, wonderfully repulsive as a bent boxing promoter. "Dennis can play nasty people very well," says Penhall. "He was doing sitcommy stuff for years and then you see him playing this nasty character with the face like the back of a bus and it's really exciting."

Also impressive are the as-yet unknown cast members – in particular the beautiful and expressive Wunmi Mosaku, as the victim's niece, and Obi Abili, as a cab operator who ends the first episode hanging upside down from a ceiling fan. "All those are young Royal Court Theatre actors," says Penhall. "A couple have done Doctor Who, but all of them are great young actors who aren't yet stars but may be one day."

Well acted and wittily written, and so exciting you can't wait for the second episode, surely Moses Jones is that holy grail for TV executives – the next serial detective. And yet executive producer Salmon says there are no plans for more episodes. "It was always conceived as an original one-off serial and that would be the end of the story. Any more would be a bonus, but it's not something we feel has to happen."

Parkes believes the character and series have legs. "I am biased. Would I like to play Moses Jones for years to come? Yes. But I also think that there is space for the series to be developed; it's such an interesting view of London – the things that go on your streets, the things you pass everyday. We don't really ever hear about this sort of London unless there's some sort of stabbing or something. It's very difficult to know what's going on in this town."

The good news is that Penhall says he would happily write more episodes. "I've had half a dozen good ideas I would like to explore and they could be single episodes of Moses Jones," he says. "It would be great to have a detective series that was aware of all the clichés and tried to subvert them. When I was a kid there was The Chinese Detective with David Yip. It wasn't well done, but it was a great idea." Moses Jones is a great idea, too.

'Moses Jones' begins on Monday on BBC2 at 9pm