Choosing to follow an Oscar nominated and then an Oscar winning turn with a relatively small role as part of an ensemble cast featuring some of the most illustrious British actors is testament to the pull of the big screen adaptation of John Le Carre’s Tinker Tailor Soldier Spy and Colin Firth plays his part perfectly in Tomas Alfredson’s film.

We had the chance to speak with the actor as part of a roundtable, and you never quite know how things will go in these types of interviews but Colin Firth could not have been more generous and considered. The actor talks about the attraction of the film, his role in particular and the essential loneliness of the men from the Circus.

After a brief introductory chat involving Wimpy Bars, Sherbet Fountains and Curly Wurlys we got in the film.

We’ll start with the obvious question – what attracted you to the film and how did you get involved?

I think it’s pretty easy. What attracted me was a no brainer – certainly if you look what else was around at the time, certainly for me last year. And the fact that I wasn’t carrying it, added to it greatly. To work with some of my favourite actors, a fantastic director, this all sounds great. It sounds platitudinous as well ‘I’ve always wanted to work with…’ but it’s true. The idea of doing it seemed very cool to me. It wouldn’t have done ten years after a fantastic TV series, it would have seemed suicidal and also would have been too close to that time for it to be retro and far enough on to feel a little out of date possibly. But I think now, 30 or so years on from the series, it seemed like a really interesting time to do it. When I heard it was Tomas Alfredson and John Hurt and Gary, it was absolutely irresistible.

You came board late if Gary was attached?

Gary wasn’t, I think. …Gary wasn’t, there was still talk about who was going to play Smiley. The script and Tomas were enough.

What did you know of book and TV series before?

Hadn’t read it, I don’t think I had. Obviously now I have. I had seen the series but not sure if I watched it at the time in sequence. It’s rather hard to remember because there are things that go so thoroughly into the popular thinking that you almost can’t remember if you’ve seen it. People talk about Felliniesque without ever having seen a Fellini film and everyone knows exactly what they mean. And I think that’s a sign something’s made an impact. I do remember scenes between Alec Guinness and Patrick Stewart, without knowing whether I actually sat down and watched it. I remember it being in the air. I remember my father talking about it. It was endlessly present. So I had a familiarity with it but don’t know if I saw it at the time but I’ve seen it now.

Was there ever a question about which role you would play?

No, I think this was the one they always had me in mind for.

He’s got a little glint in his eye though, hasn’t he?

I think he has, he enjoys life. He’s also vain, he cultivates certain eccentricities, that’s part of his vanity. He’s not just a spy, he’s a bohemian, the artist, the one who has a slightly flamboyant twist to the way he dresses and rides his bicycle into the office. And he’s sexually active, let’s say. Very active. So yeah, there’s somebody who makes use of irony which is probably very useful if you’re a spy. It’s based on not saying it exactly as you mean it.

Do you think he’s lonely?

They’re all profoundly lonely. I think that’s what the film is very much about. To me it’s a very moving and rather tender portrait of lonely men, disappointed idealists. I think Smiley is a study of loneliness. His romanticism and his view of marriage. I think he really does believe in the patriotic values of what he does and to see treachery in that area is heartbreaking. All the men in this story make considerable sacrifices in their personal lives to do what they do and I think that puts more emphasis on the fraternity they have at work. With such high stakes the sense of camaraderie is heightened and also heightened by the fact that it’s dependent on secrecy. All those things ratchet it up and to realise one of them is betraying everybody and might have been betraying them for years is not just a threat it’s also heartbreaking. And you have a world where because you don’t know who it is, it might be any of them so all their relationships are compromised. For Smiley to go to Control’s flat and see his face on the chess piece adds to his heartbreak because he realises that he too is not above suspicion. I think that’s what it’s about, it’s about the personal relationships between these men whether it’s Prideaux in his caravan, and the little boy visiting him, rather lonely little boy. Or Smiley and his marriage. Smiley at work. Or Guillam’s rather surprising scene with his partner when he realises that is no longer tenable. Ricki Tarr’s attempt at love. The girls attempt to escape. Connie’s been cut loose from the  establishment. Esterhaus dancing by himself. I do think it’s a very beautiful melancholic story and I think the thrust of it is much more emotional than intellectual.

What kind of spy would you be?
I’ve seen John Hurt on the subject and I would have to echo him – I’d be completely crap. I think it’s all very well to draw parallels with actors in terms of duplicity and inhabiting other roles and interpreting other people’s’ motives but that doesn’t mean we’d be any good if someone pointed a gun at us or we had to go through any personal physical discomfort.

A similar motive to wanting to be an actor?
Definitely. Even at best we are driven by something that’s not entirely self-serving. I do think this desire to impart your own inspiration to share stories and to communicate and have somebody on the other end, that can at its best be an important part of storytelling. But I think we are also driven by ambition and use it to suit ourselves. I’m sure that’s true of politicians, campaigners, writers, journalists, I’m quite comfortable with the idea of mixed motives.

Does the film strike a chord because of betrayal by modern politics?
I think the sense of disappointment and betrayal has been around for quite a long time. I think there’s always been disenchantment and suspicion otherwise there wouldn’t have been dissenting political movements through the centuries. So I think it’s ongoing, always feels current. So I don’t think it’s just to do with disenchantment with our current establishment. I’m sure if you talked to Americans at the time of Watergate they’d have talked about a sense of disenchantment. … I do think the sense of the currency of this material is with us. I don’t think it’s particular to now. It does feel very current. If you take the Soviets versus the West out of this all the other elements are pretty pertinent. We’ve got hacking, whether it’s Wikileaks or journalists. We know that this industrial espionage goes on and on. We’re still are paranoid and freaked out and jumping at shadows as we ever were. If it’s not reds under the beds then we’re worried about who’s the terrorist and is our intelligence any good?. I think all those things are very much alive when it comes to issues of trust and paranoia and general state of neurosis.

Were you on set when you heard about the Oscar nominations..
This came well before. We did this sometime back in October and nominations are the end of January.

Where were you went the nominations came out?
I was at the Hackney Empire doing an interview for an American television programme. I really didn’t want to have a camera rolling when the news came out but there was a television camera that had come down to set up a live link with American TV, either to see my not get it or get it.

You’re part of quite an ensemble, is that part of the film’s main draw?

I have a total of about five minute screen time in this film and it’s going to be sold on a lot more than that. But the thrill of being part of an ensemble absolutely. It is a thrill to be surrounded by brilliant people and not just because you get to watch them and it lifts your own game as well. Something I learnt at drama school. You go on a stage with someone better and that will make you better. There’s an initial moment when you walk out on set but when the scene gets going it sounds so real.

Did you enjoy the Oscars?
Some of it. I think sometimes you have to make a note to self to enjoy it. The word that comes to mind is turbulent which isn’t bad it just means things are operating at quite a pitch. It’s exciting but also can make you feel a bit neurotic because people around you feel neurotic as well. But it was very exciting. The main problem is actually taking stock and realising it’s to be enjoyed because it’s very active. You’re travelling a great deal and you’re talking about yourself a lot in artificial circumstances with microphones pointed at you and you’re probably babbling and not saying anything that represents what you really think. It’s talking. Then it suddenly happens and it’s over. It’s very odd, a slightly numbing effect I would say. I think when major things happen to us whether they’re good or bad there’s a slight shock.

Can you remember walking up to receive it?

Have you watched yourself receive it?
No. Don’t remember. That’s extraordinary. I remember thinking at the time I’ll probably wake up in July and get very excited about it. And that did happen. A month or two ago I got very excited by the fact that it had happened.

Did they cut anything out of the film that you were particularly sad to lose?
It’s funny once they’ve done it and done the final cut you tend to forget the things they’ve cut out. But yes they did cut some things out. And I suppose I was slightly sorry to lose it but I can see why. Everyone lost a scene or two I think. There was a scene, and it was a nice scene but I can see why it had to be cut, there was a scene where my character catches Guillam when he’s on the top floor trying to find the documents that Smiley has asked him for, sort of “What the hell are you doing here?” and it was a good scene but not the heart of the piece.

Tinker Tailor Soldier Spy is out in cinemas on Friday the 16th of September.