It's the first day of the Chinese New Year and Soho is not so much buzzing as banging (very loudly) with activity. And on this busiest of days, I'm walking the full length of Old Compton Street with Holby City's Jeremy Sheffield, hoping for a couple of jealous glances, or at the very least, a spot of 'being-pointed-at' action from the crowds. Disappointingly, all attention is focused on the dancing dragons, and not one double-take is thrown Sheffield's way. Which would be odd even if the man were totally unknown (sorry, but when the gayest street in the country can ignore 6'3" of extremely fit handsomeness, there's something not quite right), but when you consider that he's also a regular fixture on the nation's small-screen, well, maybe it just comes down to the fact that Jeremy Sheffield is just crap at being a celebrity. "Oh I am," he grins. "Not one person recognised me?" he checks with mock-indignation. "How dare they! I'm going to have to start wearing medical uniform when I go out."

Indeed, it's in his blue scrubs mode that Sheffield becomes immediately recognisable as Dr Alex Adams, perma-stubbled hospital heart-throb (or, for non-UK readers, 'that bloke from Nathalie Imbruglia's video for "Torn"), but equally notable, he's the only openly gay actor who constantly gets cast in straight roles and who - despite that openness - still attracts adoring female fans. This month, Sheffield returns to Holby City after a six-month hiatus, although uniform-fetishists will have to make the most of the early episodes for their scrubs fix, as he explained to Attitude.

Last time we saw you in Holby, Alex had slunk off in disgrace after impregnating one of the junior staff…

Ah yes. It was a good storyline, that. Nice one to play. It felt like a relatively realistic moral dilemma, with my character feeling that it really wasn't right to have that child in that situation. And it's a struggle that many men must go through, although one which isn't publicised or acknowledged. Obviously what the woman goes through is horrific, but I hadn't seen much about what the man goes through, which must be bloody hard.

So what have the writers got planned for your return?

Hmm. There's something quite big lined up, which I'd really like to talk about but infuriatingly I can't. But for the immediate future, I come back. In a helicopter, no less, bearing a heart and lungs for an organ transplant operation. It's all very James Bond. Oh and Alex ends up applying for a consultancy position as well, so I get to wear some sharp suits now, which is fantastic.

Not a fan of scrubs then?

Ah, you get a bit fed up with them. And before you ask, no, they never worked for me in any kind of role-play scenario.

So what have you been up to in your time off from the show?

I took six months out with no work planned, and I actually ended up working the whole time, except for four weeks. I did a short film called The Confidence Trick, an episode of Linda Green, and an episode of something called Grease Monkeys which is going to launch quite soon on BBC3 - that's a potentially amazing series, very sharp, dark, weird. Plus I got to play something very different - a vicious, very slick, yuppy bare-knuckle fighter who's a racist and a bigot but covers it up with charm.

Sounds fun - who did you base him on?

Absolutely nobody I know [grins]. Oh and I did this thing called Hearts Of Gold for the BBC…

Erk. That immediately sounds like Nick Berry/Chunky-knit-sweater territory.

I know - I'm not too sure about the title myself… But the show's fantastic - a big costume drama set in 1930s Wales. It's going to look fantastic - amazing, fuck-off costumes, and great cars. I play a doctor again, upper-middle class, goes to work at his fathers practice in Pontypridd after qualifying in London. It's all about love across social boundaries, really - Romeo and Juliet reworked.

And you would be the Romeo, presumably…

Um, yes.

Isn't this the kind of thing that showbusiness says is impossible, though? Gay actors playing convincing straight leads?

Absolutely. And I think that makes a mockery of all the phobias people have about being openly gay in this profession, it really does. Whenever we watch a film or TV, we have to suspend our disbelief. We know that George Clooney is not a paediatrician, or a surgeon, we also know that he's not in love with Julianna Margolies. And it's exactly the same suspension of disbelief when it comes to talking about someone's sexuality. Tom Hanks played a gay man years ago in Philadelphia, and everyone accepted that. It seems so obvious to me - it absolutely drives me insane.

You've done the casting rounds in LA as well - are things any better there?

I found that LA and Hollywood were particularly homophobic. It's a high-risk industry with big budgets at stake, and there's a fear - underlined by homophobia - of testing that theory. And I'm presuming that it's the money people who aren't prepared to take that risk, simply because it hasn't been done before.

Which seems odd, given how many gay men work in the industry, on either side of the camera lens…

Exactly. The really depressing thing that happens in LA is that the most homophobic people, the ones most frightened of casting openly gay actors, are actually gay themselves. And that, to me, is really twisted. I've always wondered eactly what's behind that. Oh I don't know… there may be perfectly sound business reasons for it, but I don't think so - it's all down to homophobia. Maybe there's an element of 'representation', but that whole thing does seem somewhat regressive. We should really be over that by now.

Did you like LA? Or just smirk at the silliness of it all.

LA's OK. It's strange. There's some very good things about it, and some that are not so good. And sadly, the bad stuff outweighs the good. It's very dark, very segregated and as a result has very little energy. London has much more rubbing of shoulders between communities, and that's because everyone has to use public transport. It's sort of a forced integration, but it's a good one. It's healthy. I like living in a place where you have different races, different sexualities, different ages, different creeds, different everything. LA always feels as though it's been evacuated - there's no one on the streets.

Apart from being openly gay, you've also made no secret of the fact that you're a middle-class Essex boy. Now that is brave…

Well I did make a vague attempt at rebellion. But yes, I do have that strong middle-class ethic, based on a pretty strict upbringing, actually. Me and my brother were probably the best-behaved children you could ever meet, and my instinct was pretty much to be conformist. And most kids rebel against that in their early teens - I waited till I was in my early-20s. I think it was kind of leading up to me coming out at 26, but yes, I was replacing blazers and stripey shirts with ripped jeans and so on. But while part of it was dictated by what I thought artists should look like, there was also an element of trying to find out who I was, as opposed to what people expected me to be. The problem was, I conformed quite easily. I found it easy to have a girlfriend, dress nicely, do the dinner-party thing, all of which is fine, of course, but which just wasn't me. It was more of a struggle for identity than a rebellion, I think.

Did you win the struggle?

Well, I'm comfortable with who I am these days, yes. The funny thing is, most people have a really hard time working out where I come from. Usually the first choice is Australian, then South African, then Canadian, then American.

Because of appearance or the way you speak?

I'm not sure, but it's been going on for years. I think it's because I don't have a regional accent, so I can't be placed anywhere in the UK. I used to have a much more plummy voice - prep-school, royal ballet school - and I was self-conscious about that, so I tried to lose the accent. And while a working-class British accent can be incredibly sexy, there's nothing very attractive about an upper-middle-class one - that's the least sexy thing in the world. Plus, I was involved with someone in the States, so there was a trans-Atlantic thing going on there… And I think part of it's about trying to fit in with the people around you, but there's a more pretentious side to it, which is all about aspiration. You know, trying to be something you're not because you think it's in some way desirable. The way you'd like to be seen.

Are you still single?

[nods]

I'm sorry but you'll have to account for that.

It's hardly original, whether you're straight or gay, but I tend to be attracted to the ones who are unavailable. Either emotionally unavailable, or with someone else. And you're not going to have a relationship if that's the case. I have an ongoing… sort of a relationship with someone in Milan. It's been two and a half years now, but he's not really my partner. It's down to my issues, my fears, my insecurities. I don't know. I would like one. I just don't know how to have one, to tell the truth.

Well you had a three year relationship with an American guy, so you must have some idea how it works…

Ah yes, Jody. But that was a long long time ago - how sad is that?

Well it begs the question was that relationship so good that no one's measured up since, or did it end so badly that you're not prepared to put yourself through that again?

Oh it didn't end acrimoniously at all. Jody still lives in my flat in Miami. I don't know - I think a lot of it is the fear of getting hurt, however stupid that may sound. I think I would rather be alone than be with someone just for the sake of being with someone. I need to get enough strength to have a relationship, and I'm just not there yet.

Does your fan-mail bring you offers?

There have been a few photos sent. Some of which have been very sweet, some very weird. Almost all of them from women. Eighty per cent of my fanmail is from women. And it's back to that suspension of disbelief thing - people know when they write to Tom Cruise that they're not going to end up going on a date with him, and it's the same with me.

Has anything grubby ever arrived in the post?

Not that I can think of - I did have one very weird one from an American living in a farmhouse in Lincolnshire somewhere. He wrote like a surfer dude, all 'Yo man, wassup', and said he thought the stuff I did was really cool, and that he'd done a little modelling himself and was looking to get into acting. And he listed the stuff he'd done before, and it was all major gay porn. Big Dick something, Ten Inch Sam, and so on.

Takes all sorts… speaking of, there's a certain camp value to be had from the fact that you've worked with Melissa Gilbert (who played Laura in Little House On The Prairie).

[laughs] Yep, I have bonked Laura Engels. I got on really well with Melissa, actually - she's a great laugh. I remember us talking about how awful it would be if porn was all done in a middle-class accent. You know, like Joan Collins in The Bitch gasping [adopts Stately home, High-Tea accent] "Oh, that is sooo hot". And it just doesn't work. It needs to be [adopts dimestore-hooker-on-heat American accent] "HAHT". There's something more casual, more relaxed and less uptight about the American accent.

You're a veteran of commercials from your pre-Holby days…

[winces] Commercials are so absurd - I've done about 50 of them, and you get cast to do completely stupid things. But that's good training for an actor in itself - you get used to humiliating yourself in front of a camera. You end up miming eating a bar of chocolate, miming pushing a car… I actually had to mime juggling saucepans at one point, and you can only ask yourself "Why?"

All part of the career trajectory surely. An entertainer has to look after his profile, after all…

[snorts] Profile? Basically I have no profile whatsoever in the US, and only a little bit of one over here. The only thing that anyone in America would recognise me from would be the Nathalie Imbruglia video. And I do have a manager over there, but working there would really be like starting all over again.

But that's where playing the fame game comes into it, surely. Attending the premieres, being seen at the opening of an envelope, the whole Minnie Driver thing…

Oh sure, I know that's a whole industry in itself, but you choose just how deeply you want to be involved in it. For example, I've very deliberately not ever done an interview with a daily tabloid. When I went into Holby I hired a publicist, mainly because I wanted to be out. I wanted to know which papers to deal with, how it should be done and all that. I've become a bit more savvy now. I always get the feeling that if you start using the tabloids to get your name out there, it always seems to flip around and get used back on you.

Have you been on the receiving end of that kind of treatment yet?

Not really, and let's face it, I don't have to go through what the people you see in the tabs go through - there aren't any photographers on my doorstep. I really loathe that kind of thing. Although, funnily enough I got a phonecall from my agent in Summer last year saying that because of the Attitude cover for the 100th issue, two of the tabloids were planning on running a piece about how Holby's Jeremy Sheffield had outed himself. And this was about two and a half years after I'd joined the show as an openly gay man!

Good of them to keep up with the rest of the world…

Well yes - you'd think that a national publication would actually do some research, wouldn't you? Actually, I was angry and annoyed, because I thought it had always been completely clear, and I worried they were going to make some huge sensationalist story out of a non-event. Which is neither good for me, nor for the gay community as a whole. But anyway, they ran their little articles, and nothing else was ever said about it - none of the readers cared, which is fantastic, and just shows what a non-story it was in the first place. It actually made me feel that society might have progressed a little - to a point where people really don't care.

Or maybe they still don't quite recognise who Jeremy Sheffield - 'Crap Celebrity' - is?

[grins] More than likely…

Oh nonsense. I for one am going to be telling anyone who'll listen that I've just spent the afternoon with Jeremy Sheffield.

Well you'll be hearing the reply "Jeremy WHO?" all afternoon as well, I bet…