Actor Russell Tovey graduated to Dickens, Doctor Who and Gavin & Stacey. Now starring as a modern-day werewolf in a new TV sitcom, he's headed for the top of the class

OH, I KNOW it's futile arguing with Charles Dickens – the man's dead, after all. But seeing Russell Tovey's John Chivery profess his love for Amy Dorrit during a tearful confrontation with Matthew Macfayden's obtuse Arthur Clennam simply shredded my hardened heart. "Please let him get the girl," I begged my telly, to no avail: the BBC's adaptation of Little Dorrit didn't run to revisionist endings.

Viewers have another chance to witness Tovey's special way with vulnerability – poignant but never pathetic – with the return of Being Human. Last winter's pilot proved so popular that BBC3 commissioned six more episodes, which began airing a fortnight ago. Tovey, 27, plays George, one of an unorthodox triumvirate of twentysomethings sharing a Bristol flat. As if getting ahead in the world wasn't hard enough at that age, George is a werewolf, Mitchell a vampire, and Annie a ghost.

Tovey is the only original cast member returning to a show he described as "like a cross between This Life and Buffy the Vampire Slayer." Wasn't that awkward? From the back of a taxi hurtling through London's theatre district, his candid reply crackles down the line.

"It was nerve-wracking. The pilot was a success and I loved working with Andrea (Riseborough] and Guy (Flanagan], and felt like, well, if it was so good and the feedback was so good, why mess around? I was nervous and slightly resentful, so I went into it kind of worried. Then we sat down for a reading and I was like, oh," he sighs with relief, "it's completely fine!"

Unaware that when his curiosity is piqued, Tovey dives in headfirst, I jokingly inquire whether he unearthed any cool werewolf lore doing his preparation. He regales me with facts and figures, including the horrifying statistic that in France, between 1520 and 1630, some 30,000 people were tried for being werewolves, many of whom were subsequently burned at the stake. "Isn't that just crazy," he marvels.

He paints an amusing portrait of the artist as a young eccentric, explaining that as a kid growing up in Billericay, he was prone to collections and crazes. His parents, who run a coach company ferrying the denizens of Essex to Gatwick, were wonderfully supportive.

"If I said I was interested in fossils, they'd take me to an archaeology dig. If I said I was interested in history we'd go to a museum. I had a metal detector and I'd go off for hours. I collected coins, then I became obsessed with rocks and minerals. For my eighth birthday we ended up going to the annual rock and mineral society convention! My parents were like, 'What the hell have we brought up?' Then I wanted to be a history teacher, and then I saw Dead Poets Society and The Goonies and Stand By Me, and I remember thinking, 'That's it, I want to be an actor.'"

He's worked steadily since he was 11 years old, though that caused some tension at home. His father worried that Russell was missing too much school, and his mum insisted that the boy should be allowed to follow his heart. Rather a relief, he admits now, that the acting paid off!

The turning point for Tovey, and indeed the entire cast, was three years spent performing The History Boys in every format – on stage around the world, in the film version, and for a radio transmission. I'm not the first journalist to notice "The Alan Bennett Effect", but I wonder how Tovey sees it.

"Alan Bennett is a starmaker, he's the Simon Cowell of the theatre world! He's a beautiful, beautiful man, completely humble and so accessible. I was a fan long before meeting him, we all were. It was such an honour that he quickly became 'AB' and loved being one of the boys. When people start pandering to him he gets a bit uncomfortable."

What did Tovey learn at the Master's feet? "So much that I don't even realise. What I've been given by him is… opportunity. Three years spent on a job that was amazing. Because it was so successful – as a young actor, if people want to attach you to stuff and talk about you, they need a handle and for all of us, The History Boys is that handle. We'd all worked before but that was a proper milestone, where people start taking notice."

He also reckons his time at the National Theatre in London – where he took advantage of all the workshops and readings – offered incredible training which more than made up for his insecurities about not having attended drama school.

Tovey writes plays and screenplays, and considers himself privileged to have 'AB' as an early reader. He points out that we have Bennett to thank for Gavin and Stacey. "James (Corden, the co-writer and co-star] told him, 'I'm thinking of writing a show,' and Alan sort of gave James the balls to go ahead and do it. Everyone (in the cast] would be able to say he's given them something specific."

The friendships among the boys have had a knock-on effect professionally. There's a noticeable posse of talent performing in one another's shows. I'm particularly thinking of the swirl around the James Corden/Rob Brydon nexus, since Tovey played Budgie in two episodes of Gavin and Stacey and a gay producer in Rob Brydon's Annually Retentive. Tovey is keen to shrug off the 'nice guy' mantle and tackle a few creeps. He's getting that opportunity with A Miracle, which begins rehearsals today at the prestigious Royal Court Theatre. It's the story of a soldier returning from Afghanistan who expects a hero's welcome, only to face indifference and resentment. He clashes with his family, treats the girl who loves him shabbily, and leaves a trail of emotional devastation in his wake. Sounds depressing, I say. "Yes, but it's the Royal Court and this is what they do best," he jokes.

If this year is as busy as the past one, Tovey will move into London, not least to save on extortionate late-night taxis. But it'll be a wrench leaving his close-knit family – his parents and an older brother and his fiance who have two boys, Nathan and Mackenzie, aged four and two.

This closeness is all the more precious because it follows a falling-out with his dad after Tovey revealed his sexual orientation. "I came out to myself when I was about 15 or 16, and to my parents when I was 18. When you come out to your parents, that's when it's properly official," he says.

"Me and my dad just crossed wires. We have an amazing relationship now and did when I was growing up, but there are underlying things that don't get covered. When I came out he found it very odd and didn't know how to cope. I think my parents thought, 'OK, you're gay, you're going to get Aids,' and were under the impression that if I'd told them sooner they could have done something about it."

Done what – 'fixed' the so-called problem? "Yeah, like a hormone treatment or something. I think he was uneducated because it's not his world. My dad handled it the way that he thought was right, and for me it wasn't right.

"When my brother and his fiance had their first kid it just sort of evaporated. It seemed really insignificant that I slept with men rather than women. Suddenly, this little boy was so amazing and he's going to love his uncle and his granddad and his dad, and if he sees them arguing that's going to be horrific, so it just went."

Without wishing to become a poster boy for the cause, he says: "The only thing I can give to young gay people is that when I was growing up there were no role models that were blokey, that were men. Everybody was flamboyant and camp, and I remember going, 'That's not me, so even though I think I am gay, I don't think I fit into this world.'"

He's currently single, though I teasingly suggest that if he keeps getting his kit off during werewolf transformations he won't be short of admirers. "I've got really good friends and family. My parents, after 30 years, are still incredibly in love, still make each other laugh, which is a beautiful thing to see. And my brother and his fiance are completely happy, so if I feel a bit lonely I just go and sit with them and feel their love."

Sentiments like that ought to make me hurl into a bucket, but it's like I was saying, Russell Tovey is sweet without being cloying. He may profess relief at not becoming the new Doctor Who, despite a ringing endorsement from Russell T Davies – "I don't know if I'm ready for that sort of massive attention, you're like a pop star" – but I predict it's only a matter of time before his name appears above the title.

&#149 Being Human airs Sunday nights at 9pm on BBC3. A Miracle opens at London's Royal Court Theatre on 27 February.