Welcome to the world of Jonathan Firth, a funny, sometimes panicked but very lovable 27 year old actor on the brink of stardom. And make no mistake, Firth is going places -- that bank manager will soon be crawling over broken glass with his mortgage papers. “I moved out of my last flat two months ago and I’m crashing at my brother’s place,” he says. “It’s a good job he’s away at the moment, I told him I’d only be staying a fortnight.”

The sexiest leading man in breeches, Colin, may now be spending most of his time in Rome with his new Italian fiancee, Livia Giuggioli, but Jonathan is all ours. So, is he angling for some of his 36-year-old brother’s success? Firth lets out a loud laugh. “Would I like to be a huge sex symbol and earn lots of money playing high-profile parts?” he asks jokingly. “Of course I would. It would be a fate worse than death but hey, I think I can handle it. I was overseas when Pride & Prejudice was on TV, so at the time I didn’t fully comprehend how successful it was and how it had made Colin. It was only when I went to the press launch of one of the shows I did for the BBC that I realised just how big Colin had become. Suddenly there was this huge crowd of journalists swarming around me, all asking the sort of questions only he could answer, like is Colin getting married and will he be doing a sequel to Pride & Prejudice?”

“It was incredible and rather aggressive. I felt for him a little. I mean, he and his girlfriend are constantly followed by the paparazzi, which can get a bit tedious. But it’s the price you pay. The extraordinary thing is, Colin never gets recognized in the street. Because most of his work is costume drama, people expect to see him walking around Sainsbury’s in frilly shirts and top hats and tails, so he gets most of the perks without the drawbacks.”

Firth has yet to reach the dizzying heights of adoration his brother enjoys. Since leaving drama school seven years ago, he’s been in work constantly, including a year-long, worldwide tour with the Royal Shakespeare Company, plus TV parts in Cadfael, Inspector Morse and Middlemarch. But to date, all his roles have been about as romantic as Hannibal Lector. “I’ve always been cast as the killer or the mad one,” he sighs.

But all this is about to change in the autumn when we’ll see him on ITV as Sergeant Troy, the dashing hero of Thomas Hardy’s Far From The Madding Crowd. Yes, he’ll be on a horse. Yes, he’ll be in breeches. And yes, he’ll be all dark and moody. The only thing missing is a wet shirt. Everyone, including Firth himself, knows it’s his biggest break yet. “I can’t quite believe it. I’ve always wanted to play a romantic lead role like Mr. Darcy, but was never offered one,” he says, smiling widely. “Even when Colin was unavailable for roles like that, they never asked me. I’m thrilled about Sergeant Troy. It’s the sort of part which can propel your career overnight. And Troy’s in uniform, so that’ll help sway the ladies...”

As far as his own love life is concerned, Firth is currently single. In fact, he’s never made it to the moving-in-together stage with any of his girlfriends. He denies being a pig, a bore or a bastard, and claims to be dream boyfriend material. So how come he's always a Norman No Mates when it comes to shacking up? "Maybe I'm not grown up enough yet," he says with a little-boy-lost smile. “Right now, being single doesn't bother me, but ultimately I'd love to live with a girl and get married. Trouble is, I'm very set in my ways. I have to be left alone in the morning to get on with my rituals of reading and eating - without conversing. I'm really a wonderful person to be in a relationship with, sweetness and light and all those things, except for the first 45 minutes or so after I wake up. I love living alone, but I do worry it's sending me mad. That's why I want to buy a two-bedroom flat, so I can install someone else to monitor me and tell me when I'm talking to myself. I certainly don't want to become one of those sad old actors who's still living on their own with lots of animals when they're 50. I'm very, very desperate that should never happen. I'm not commitment shy, I have no problem sharing space with people, it's just that there's never been a need to co-habit. Because most of my girlfriends have been actresses, there have been times when we've both been out of work and spent 24 hours a day together. With the right person that can be wonderful."

Great. So he's one of those types who only dates actresses? "No!' He practically spits. "l don't date only actresses, it's largely down to who I meet and that usually means people I work with, And it helps to be with someone who leads a life as strange as mine. Especially when it comes to love scenes - not many girls are as understanding as a fellow actress when you spring out of bed in the morning and spring into bed with another woman a few hours later."

When it comes to donning flesh-coloured G-strings on set, Firth is something of an expert, When the script has called for it, he's flashed his flesh and played tongue sarnies on four or five occasions, including his most recent romp, which saw him writhing around naked with Brit babe Emily Mortimer in the ITV drama Midsummer Murders. "Love scenes are very surreal, mainly because you're doing them with someone you've known for about four hours, in a bed full of breadcrumbs with 50 people looking on," he shudders. "lt’s so unerotic. I've never had to worry about doing anything embarrassing. In fact, they can become so mundane you find yourself lying in bed, virtually naked, thinking about the best route into work, But even more embarrassing is the voice-over you have to do later, I once had to record a 30-second orgasm off-camera, and standing there grunting and groaning in a room full of people was mortifying."Thirty seconds is a long time to fake something like that." You're telling us...

So, why acting? "I hated school, never really got along with it," explains Firth, who grew up in Winchester. "But I did enjoy the Saturday morning drama club that Colin, my sister Kate and I went to in the village hall. Both my parents are retired college lecturers so, if anything, the drama club was responsible for the acting bug. Although Colin had already begun to act, my parents weren't too thrilled when I announced I wanted to go to drama school but couldn't explain why. All I knew was I liked being in plays, so drama school seemed like a good way of carrying on with it, But that was the limit of my ambitions, so it was kind of a surprise when I left and someone actually gave me a job." When Firth was accepted at London's Central School of Speech and Drama, he packed a rucksack and two cardboard boxes and arrived on Colin's doorstep looking for a place to stay. The arrangement lasted just three months. "Poor Colin, I've gone full circle," laughs Firth. "He’s got me back there now. When I first came to London I only stayed at his flat for the first term, then I moved into a student house, which he was probably quite happy about."

After leaving Colin's cosy abode, Firth embarked on a series of cider-fuelled student house shares, often living in conditions you wouldn't wish on your worst enemy. At one point his least favourite night-time ritual was flicking slugs off the bedroom wall - and that was after he'd mopped the running water from the ceiling. "I lived in some truly horrible places," he says. "My first student house was in glamorous Peckham and I spent two years there drinking lots of Merrydown cider and eating baked beans because I'd spent all my grant in the first week. Then there was a particularly repulsive place in North London that was infested with fleas. When it rained the house would flood, and slug flicking became my hobby. I hated every minute there. As a student I was always so skint. God knows how students today manage, the grants are so small. You can't even bunk your fares around London any more because of the ticket barriers. In my day, you could buy a one-week Travel Pass and use it all year if you flicked it under the inspector's nose quick enough," he laughs.

"It's a good job I'm not a big spender or I'd still be paying off my student debts. I've always liked spending money, it's just I can never be bothered to go out and actually do it. It always seems like such an effort. You only have to look at my wardrobe to see how much I hate shopping for clothes; most of it is made up of garments I've got from productions I've been in. And when you consider most of my work has been staged in medieval and 18th-century times, you get a picture of how badly dressed I am." Mmm, but we reckon he'll scrub up all right in a tight pair of breeches... ·