Is it true you’re a big Paolo Sorrentino fan? Is that why you signed on to Parthenope? I’ve seen all the films, and I absolutely love his movies… I’d have done anything for him. I actually wrote back and said ‘I’d play a shadow on the wall. I will just come and do anything, to be a part of one of your films.’ I’m obviously thrilled to be a part of it. 

You’ve played many real characters before, and here you’re author John Cheever. Are you ever fearful taking on real people? Not fear. I almost feel that George Smiley [in Tinker Tailor Soldier Spy] was real, in a way, because it was such an iconic character, and made even more so by Alec Guinness. So that was a bit fearful going into that. And then there was Churchill who was again iconic and possibly the greatest or most well-known Englishman who ever lived. This is a little different because I’m playing John Cheever and I’m not playing him. In as much that he is a melancholic, big, romantic, drunken construction of Paolo’s. He’s Paolo Sorrentino’s John Cheever.

How do you choose your roles? Do you have a career plan? I have no plan. I don’t think I’ve chased anything I’ve ever done.

You never directed again after 1997’s Nil By Mouth. Is it simply a case that you won’t compromise on budgets? I’ve been in films where they promise one thing, and then they cut the budget, and then we haven’t got the days, and then they’re tearing pages out of the script, and they’re changing the story, and then it’s all what I call a ‘fuck, bollocks and a scramble’ at the end of the day. They’re like ‘we’ve got to be out of here. We just got to shoot and get the scene.’ And I don’t want to work like that. I can work like that as an actor and earn far more money than spending two years of my life on a film, my own film, to then stand at the back of the Palais [in Cannes] if I was lucky enough, and go ‘I should have listened to myself.’ I’d rather not do it. 

That aside, are you at a very happy stage of your life? I’m at the happiest I’ve been. I’ve been sober a long time. Without that, I wouldn’t be sitting here today. I’d be dead. I know that for a fact. I’m 27-and-a-half years sober, so that’s a big deal, and things have come my way since then.

Do you have trouble recalling the pre-sober movies you made? Well, I know I’m in The Scarlet Letter because I can see it. I don’t know if I remember making it, but I know I’m in it because I’m on the screen. I wasn’t drinking on the set but it just becomes part of your life. You would go to work, and then you finish in the evening, and then you would go home and drink. And when you weren’t working, or at the weekend, you drink more than you normally would in the week. It wasn’t like I had a flask in my costume and I was guzzling at vodka in the corner. 

You were also famed for over-the-top characters, like your corrupt cop in Léon. Were those fun? Léon is a cartoon, isn’t it? It’s like a James Bond villain. That’s just me having a laugh! When we were shooting Léon, a guy [on screen] came up to me and I’d say ‘bring me everyone’ and he said ‘everyone?’ And I’d go ‘everyone.’ On one take, I went to the sound guy and said ‘I’m going to do this one really loud so be prepared. I’m just going to make Luc [Besson, director] laugh as a joke.’ It was a joke! So we did the take and went ‘everyone!!!’ and he kept it in. It was just me having a giggle.

You’ve had great success in Slow Horses. How do you feel about your character, Jackson Lamb? It’s my pension! I feel very lucky, very privileged, to get a project which is that good.

Parthenope is in cinemas from Friday 2 May; four seasons of Slow Horses are available on Apple TV+.