The rehearsal room for Educating Rita sits high up on a corner of the Menier Chocolate Factory building, just south of the Thames. It is gloriously, romantically shabby: a sheet is tacked up in place of a door, two portable heaters provide pockets of warmth, and the morning sunlight floods dusty floorboards. For Larry Lamb, the actor playing jaded lecturer Frank Bryant, it must be quite an adjustment after two years in EastEnders, in which he played the psychopathic Archie Mitchell, dispatched with a blow to the head on Christmas Day.
We sit at a rickety table in front of Rita's simple set. "The turnover, the scene after scene after scene in that factory," he says, of EastEnders. "You're churning that stuff out, some of which can be really testing. So yes, it's interesting to come back to something like this that you can really focus on."
Lamb has been "banging around for 30 years". At the age of 62, he says he feels as if his career has been given a late boost, thanks to EastEnders and the success of Gavin and Stacey, in which he played Gav's dad Mick. "The fact that I was in those shows probably has a lot to do with my getting the part of Frank. EastEnders gives you a huge, weird amount of fame, but then you leave and the spotlight dims. I'm just an actor who was in a couple of popular programmes. But if it bumps you up the ladder a bit, and you become more commercially interesting to producers, then thank you very much."
As Frank, the cynical Open University lecturer who opens hairdresser Rita up to the world of literature, Lamb follows in the footsteps of many big-name actors. He hasn't watched Michael Caine in the film version, and didn't hear Bill Nighy in the recent Radio 4 adaptation. "I try not to bring any baggage," Lamb says. "I don't want to get involved with anyone else's interpretation."
Lamb didn't even think acting was for him until his late 20s. His childhood had been overshadowed by his parents' divorce and his father's psychological abuse: in interviews last year, he said he had modelled the manipulative, controlling Archie Mitchell on his father. "He was a bully, who had been bullied by his own father," he says now. "He dominated me as a child. I lived in fear of him." His mother left when he was nine, taking Lamb's sister; Lamb and his brother remained with their father. "My mother had to leg it because he was such a nightmare," he says. It must have been terrifying to be left behind. He nods. "We went to live with him, but in his mother's house, and my grandmother was very influential on me. She really mothered me, which is what I needed."
As a child, Lamb wanted to be a doctor, but he wasn't any good at science. Mostly, he just wanted to get away from home. He moved to north America, becoming a manager for an oil pipeline company. He was 27 when he joined a local drama group. "I just needed something different, and I wanted to be around people who were worldly and knew about the arts." Educating Larry, if you like. "I guess I was of an artistic temperament, but I'd tried to force myself into things that were not really for me."
He moved back to the UK, getting a role in the BBC soap Triangle, set on a ferry, and has worked steadily since, on TV in A Touch of Frost, Spooks and Our Friends in the North, interspersed with stage roles for the National and the RSC. His father took no interest in his career; when he died in 2008, Lamb had had no contact with him for 15 years.
He thinks the damage his father caused could have been more lasting if he hadn't had therapy in his 30s, and again in the 1990s, when he joined the cast of Art, Yasmin Reza's long-running West End play. "I was on a good salary, I had a very fixed life, so I could go five days a week for three months," he says. "[Therapy] was extraordinary, quite traumatic, but in a glorious way. It was a release, a joyous experience, getting it out. I began to understand what had been done to me, and how deeply he had forced himself in to my psyche, and then you can start to put things right."
Lamb, who has two daughters aged six and 10, is proud of his relationship with his own son from his previous marriage, the TV presenter and radio host George Lamb. "I wasn't well known when he was growing up, so all the success he has had, he's done by himself."
EastEnders gave him security, but he enjoys the unpredictability of being a jobbing actor. "I had settled in to EastEnders, because it becomes your job," he says. "I think if they'd asked me, I'd have stayed on, but I don't think that would have been a wise decision. When you're off that rollercoaster, you're in your own world again. It's an amazing show to be involved with, but now it feels natural for me to go back to what led me there."