INTERVIEW: It Doesn't Get Bigger For Mr Who?

IT'S THE last shot before lunch, and Casanova is wilting. An old scene-hand has just wandered on to the set, singing "You make me mad, you make me sad," and after he's been silenced by a chorus of "Shhhhs", the man who might just be the Scottish acting profession's best-kept secret goes for the umpteenth take.

"I know what men think about," says the great lover, played by Paisley's David Tennant. "All day long, those stupid little inches, driving you mad." Casanova is interrogating his rival, Grimani, over a perceived problem in the breeches department. "Is it big? Is it big enough? Am I any good at all? Is every other man better than me?"

Grimani suggests that Casanova seems to be more in love with men than women, which may or may not be a line added to the lothario's diaries by screenwriter Russell T Davies of Queer As Folk notoriety. Casanova taunts him some more: "Look, if you want a measuring contest, I'll drop my pants right now and I'll win."

Grimani executes the 12th or 13th none-too-manly slap
to Casanova's right cheek. Finally, the director has got his shot and I've got my exclusive, on-set peek at next year's big BBC blockbuster.

Five minutes later, in a caravan marked 'Casanova' in a Manchester car-park - and I really hope he's snapped himself next to this sign for his scrapbook - Tennant can rest his thigh-length leather boots on a heater, cover his ruffle with a napkin so he doesn't stain it with gravy or mushy peas, and ponder the question of what his father will make of such an empurpled production. Dad, you see, is a former Moderator of the General Assembly of the Church of Scotland.

"Both my parents will be fine about it," he says with a chuckle. "They've seen me do a lot worse: gay love scenes, running across the stage in the buff... they're not high-church-holy, they're worldly and really pretty liberal."

Most of Tennant's career to date - he's 33 and been London-based for 10 of them - has been spent treading the boards. Togged-up and bare-arsed, he's hoofed it for the National Theatre and the Royal Shakespeare Company for a good 10 years. As a result, he's remained a handsome stranger to the wider, channel-hopping public.

But now this self-confessed "fame-dodger" finds himself on the brink of stardom. Casanova isn't due until next March, but he's also got a lead role in 2004's big BBC blockbuster, Blackpool, and that starts this week.

"It's very exciting - bloody mental, in fact," says Tennant. He might have added "wizard" because he's also grabbed a part in the new Harry Potter epic, The Goblet Of Fire. "I try not to think about all the stuff I'm doing. If I did, I'd never turn up for work."

Blackpool owes a debt to another Potter - Dennis. Britain's greatest TV dramatist knew all about the potency of cheap music, and for this six-parter writer Peter Bowker makes his characters burst into song in the style of Pennies From Heaven and The Singing Detective.

David Morrissey gets things going with Elvis's 'Viva Las Vegas'. He plays Ripley Holden who, with a name like that, could only be a north-east megalomaniac. In the land of the one-armed bandit, Holden is king. Not even the discovery of a bloody corpse in his amusement arcade knocks him off his stride along the pier to even greater power and greed. But he hasn't reckoned on the sarky Scottish sleuth, Peter Carlisle.

As the dogged detective, complete with Colombo-esque raincoat, Tennant is required to break off from the cracking script - at one point Morrissey dismisses pension plans thus: "That's just gambling without t'fun" - to mouth along to Nancy Sinatra's 'These Boots Are Made For Walkin', Kenny Rodgers' 'The Gambler' and The Smiths' 'The Boy With The Thorn In His Side'.

"Carlisle is a maverick cop in the traditional manner," smiles Tennant, who may not have done anything as big as this on the small screen before but is well aware that maverick cops are as commonplace as quirky docs.

For its sheer wackiness, however, he reckons that Blackpool stands out from the crowd. "TV doesn't take enough chances these days and it's quite risky to stick something as mad as this on to prime time."

Maybe it's a gamble for a TV heavyweight like Morrissey, most recently seen in political dramas, including one as Gordon Brown. But surely it's less of one for Tennant, who cheerfully admits that his last telly role of any substance was Takin' Over The Asylum all of a decade ago, and that if Blackpool beaches and Casanova, ahem, stiffs - a highly unlikely scenario - he'll be just as happy to return to the stage.

EVEN BY ACTING standards, his relationship with the profession - from first stated ambition to the present - is unusual. "I know this sounds rather fanciful, but I reckon I wanted to be an actor from the age of three or four. That was when I first saw Doctor Who, the Tom Baker version."

But every boy wanted to be a Time Lord at that age - didn't he flirt with other career options? "No, never. I was peculiarly single-minded. I was aware of what an actor did right from the start because I quizzed my parents about it. I didn't think I was being particularly belligerent, but looking back I suppose it was a pretty extraordinary stance to adopt, especially coming from Paisley.

"I hated school [Paisley Grammar], hated my teenage years." The only anecdote he offers up from this period is the night he was beaten up. His attackers decided he was a goth, yet his only fashion crime was wearing a bootlace tie in the style of Bono. (Actually, that's deserving of a biffing.) "I was spotty with greasy hair and pretty pissed off. I couldn't wait to get to drama college [RSAMD] so that my life could get going.
"My parents did try to dissuade me - quite right, too, because acting is a stupid profession - although my dad had to admit he'd contemplated it in his younger days."

The Rt Rev Dr Sandy McDonald, now retired, was minister at St Mark's Oldhall and Moderator in 1997, and Tennant - the name-change was forced on him by Equity; his mother refuses to acknowledge it - reckons there must be a bit of the actor in every man of the cloth. "I remember as a boy watching him preach from the pulpit and thinking: 'That's not Dad.' His passion scared me."

So who is God to him? "I don't think, just because I'm the minister's son, that I must believe. My parents allowed me to come to my own conclusions. Let's face it, organised religion, especially in Scotland, leaves a lot to be desired and the Church of Scotland in particular has a lot to answer for. But I think I have a humanist outlook because of them - Christian in the right way."

So how often does ho attend church? "Jings, they'll be reading this. Well, I have been very busy... "

Tom Baker remains Tennant's idol. "People think I'm kidding when I say this, but I really do believe that his Doctor Who is one of the all-time great performances." He reckons Baker is "probably as mad as a tree full of snakes" but doesn't want to meet him in case the illusion is shattered. And although he's nabbed the title role in Russell T Davies' Casanova, you don't have to ask if he would have swapped it for even just a walk-on in the same writer's revival of the time-travelling classic.

Casanova, in which the hero is revealed as the original 18th century metrosexual, and more immediately Blackpool, will render redundant the question "David Who?" and mean Tennant gets spotted in the street by more than just his traditional fanbase of RSC-subscribing little old ladies. But the "currently single" actor is unfazed by an impending fame that will be further enhanced by his Pottering about as Barty Crouch Jr.

"After Takin' Over The Asylum, I didn't want to hang around waiting for a part in EastEnders," he says. "My first London agent told me that the way to build a long career was in the theatre, and when I got into the RSC, and climbed the ladder to play Romeo and suchlike, I was thrilled. It was more than I could ever want, and no matter what happens to me now, I'll never regard theatre as the poor relation."

It's time he was back on the set for the next phase of the transformation from Romeo to Casanova. I tell him that an hour in the company of someone so "peculiarly single-minded" has been exhausting; he laughs and reminds me of his chosen profession.

"I've been very lucky because if I hadn't been able to make a living doing this I don't know what would have become of me. But I'm like every actor: just waiting to be found out."

Blackpool starts on BBC1 on Thursday at 9pm