Russell T Davies interview: Feeling regenerated

"Obviously, I'm going to live for another century, but when my gravestone is finally written in a hundred years' time, it'll simply say: Queer As Folk," he laughs. "The vicar might complain." The vicar might not be the only one to complain. For surely there is another wildly successful, pioneering series for which the 46-year-old TV screenwriter and producer will be just as well remembered: the regenerated Doctor Who.

Davies plays down his influence on the show, which he revived with such memorable results in 2005. "I feel I'm just a caretaker of Doctor Who," he says. "Hopefully there'll be hundreds more writers on the show after me." But the fact remains that Davies, as the show's "story-liner" and executive producer, has played a key role in the most successful popular TV drama of the new millennium.

It is hard to overstate his significance. The intergalactic success of the reborn Doctor Who has turned Davies, whose TV career began with a 1991 children's series called Dark Season, into the most in-demand writer in British television. Alongside Lynda La Plante, Jimmy McGovern and Paul Abbott, Davies is one of only a handful of British TV writers who have "above the title" status – they are often better known than the stars in their projects. It is no surprise that two years ago Davies was ranked at number 15 in a poll of the most important people in the British media.

In addition, Davies enjoys "green-light" stature – the mere fact that his name is attached to a drama can be enough to get it commissioned. On the back of Doctor Who, he has launched not one but two spin-offs: Torchwood and the children's series The Sarah Jane Adventures.

What distinguishes Davies' writing is his ability to relate powerful universal truths through very specific and compelling human stories. In, say, The Second Coming – in which future Doctor Who Christopher Eccleston played a reborn Jesus Christ – he was able simultaneously to grapple with the immense life-and-death questions that have taxed theologians for millennia and tell an immediately identifiable, everyday tale of love and loss. In Davies' work, the personal and the philosophical fuse seamlessly.

In every sense, the six-foot-six Welshman – he hails from Swansea and read English at Worcester College, Oxford – is a hard figure to ignore. He makes for a charismatic interviewee, crackling with the sort of electricity that would serve him very well if he ever chose to work on the other side of the camera. His sole appearance thus far was presenting a single episode of the children's series, Play School, in 1987. But should the writing ever dry up, he could surely carve out a second career as a performer.

Davies is at ease in the spotlight. Even so, the high profile that he has attained since working on Doctor Who has taken the writer aback. "Doctor Who has had an extraordinary effect on my profile," confirms Davies, who has lived in Manchester for many years with his partner, a customs officer, Andrew Smith. "Partly, it's my own fault for being so gobby.

"But it's also because it's a very big show that only has two regular leads. An equivalent American show would have eight leads. But the actors playing The Doctor and his companion simply can't do all the interviews, so Muggins here has to step forward. I'm no shrinking violet, but whenever I see a huge picture of myself in the papers, I think, 'Oh God, now I have to kill myself!' "

As a youngster, Davies was a card-carrying Time Lord aficionado (known in the trade as a "Whovian"). He recalls his astonishment at the immediate success of his revival of Doctor Who after a 16-year absence from our TV screens. "It did take me by surprise. It's not even as if it was subtle – it was all big monsters and massive explosions. It was a very bold show drawn in thick felt pens, but there was nothing else like it for a family audience. Television goes in cycles and things get forgotten. A couple of years ago, we'd have said that Opportunity Knocks and Come Dancing were dead, but the modern variations are now the biggest shows in the world.

"People thought that Doctor Who's heritage would count against us and that to the children of today it would look old-fashioned. But in fact that worked in our favour. The fact that their parents had loved it made children interested – and then they made it their own.

"There is such an appetite for fantasy. Look at the recent rise of the graphic novel. In good science fiction, it's impossible not to say something about the world we live in. Viewers inevitably see something about their own world, but in a heightened way."

Recently Davies announced that he was stepping down as executive producer of Doctor Who. It's a decision that has allowed him to focus his attention on Torchwood, the spin-off series about Captain Jack Harkness (John Barrowman), a former ally of the Doctor's who runs a secret government agency countering extra-terrestrial threats to our planet. Davies has scripted the latest series, "Children of Earth", which has moved for the first time to BBC1 and is being shown on five consecutive nights from Monday. The disturbing story charts the increasingly frantic efforts of Captain Jack's team to avert an alien invasion. The imminent attack is heralded by every child on earth, who, in a spookily gripping image, all stop at the same moment and in a trance repeatedly chant "we are coming". At the same time a covert government operation run by the shady Mr Frobisher (played by Peter Capaldi) poses Torchwood a very grave threat indeed.

Even though he will leave Doctor Who at Christmas, Davies will continue to executive produce Torchwood. "I couldn't abandon it now," he says. Is it hard, though, to wear two hats? "I look good in two hats – one with a little jaunty feather and one more substantial, serious affair," smiles Davies. "Working on both Doctor Who and Torchwood is like having everyday conversations with different people. If you talk to a child and then to an adult, you use different voices. I know where to pitch stuff.

"You can get darker in Torchwood. Doctor Who is fundamentally a very optimistic show – that's in its DNA. It's the story of a man who travels through time and space for no good reason. That's very important to the show's success. He's not a detective, so why is he doing it? Because he loves it. That puts a basic optimism into the show. Torchwood is more earthbound. It looks the human race more squarely in the eye. "Children of Earth" is an allegory about how we view the developing world. When a country like Rwanda or Zimbabwe falls under the rule of martial law or commits genocide, we sit there in a state of some complacency thinking we're more civilised than those countries.

"But that's so wrong, especially now so many of our politicians have been discredited. The government are now saying they shouldn't call a general election because the vote would be panicky! But we could have extremist parties in Parliament, and the political landscape could change overnight.

"That's what "Children of Earth" is about – how everything we call civilisation could snap just like that. We're not better than the people living in Zimbabwe. We're in trouble, and we've created it ourselves. That's not a story I'd choose for Doctor Who."

The other reason Torchwood works so well, of course, is the magnetic figure of Captain Jack. "John Barrowman, God bless him, is a national institution," declares Davies, "but because he's so happy, you forget he's actually playing something quite radical in Torchwood. Men love this gay character, and that's never happened before. I think we've crossed a bridge here. Of course, there are many more to cross – pretty Chinese ones beside willow trees would be my personal preference."

Davies says he has no regrets about vacating the Tardis. "Not one bit of me thinks, 'Ooh, I've made a mistake, I wish I was doing Doctor Who next year.' I've never before stayed for so long on one job. Now I want to leave on a high and go and scare myself somewhere else."

As Arthur Daley put it, the world is his lobster. Davies, it would appear, can name his next project. "It's nice to be in this position," he says. "But nothing can be guaranteed a commission. We're in the middle of a recession. We're facing tough times. I may have to start digging up radishes with my bare hands. Imagine what I'd be wearing."

Torchwood – Children of Earth begins at BBC1 on Monday at 9pm.