From Mad Men to The Crown, the actor is used to big exits. As new disaster drama Chernobyl launches, he talks about cover-ups, climate change shame – and his hellraising dad Richard

Jared Harris says that if only he had played Lane Pryce as he was meant to, he would have probably lasted the duration of Mad Men. Pryce, the financial executive at the TV drama’s advertising agency, was supposed to be a right bastard – and the show’s creator Matthew Weiner famously said baddies don’t get written out. But Harris doesn’t do bastards. He will always find a way to humanise a character – a sprinkling of vulnerability here, a dash of tenderness there. And sure enough, three seasons down the line, Lane departed.

Harris is getting used to being bumped off. His quietly dignified George VI in The Crown was inevitably done for by a coronary thrombosis. In his latest TV drama, Chernobyl, Harris’s investigative scientist has died before the opening sequence is done and dusted. (Don’t worry, he’s still the lead.)

“My wife said, ‘I can’t believe it. Why are they doing this to you again?’ It’s a problem career-wise.” Does he mean that? Well, he says, if he were more money-minded, it would be problematic. “If you die in everything, it means you’re not in a sequel – or, if you’re in a series, you’re not in the next one.” He smiles. “But I’ve never tried to jump on board a franchise, so I was being slightly facetious about that.”

Facebook Twitter Pinterest A dash of tenderness … Harris with Naturi Naughton in Mad Men. Photograph: Everett/Alamy

Perhaps it’s the lot of the character actor – fascinating parts that end with a bang. And in recent years Harris has established himself as one of our finest. He has also established himself as a man with immaculate taste. Mad Men, The Crown and The Terror, about the Royal Navy’s treacherous 19th-century trip into the unknown, are three of the great contemporary TV dramas. And Chernobyl looks like it’s going to be another.

A tense, beautifully written five-parter about the 1986 catastrophe at the nuclear power plant, Chernobyl tells the story of one of the great attempted cover-ups of the 20th century. The Soviet Union was determined not to let the world know that the core of the reactor in Pripyat, northern Ukraine, had exploded. Telephone wires were cut, people were not allowed to leave the city, and the official in charge of the investigation announced that locals had been exposed to radiation equivalent to a chest x-ray.

Meanwhile, Harris’s Valery Legasov is determined to tell the truth – whatever the cost. Officially 31 people died as a direct result of the explosion, but the World Health Organisation estimates that 9,000 died from radiation exposure, while another estimate puts the figure as high as 60,000. It is believed that the area won’t be safe for human habitation for 20,000 years.

“They just didn’t want to accept the consequence of that reality,” Harris says. “In the end, it was the outside press that forced them to accept what happened. That’s shocking.” He believes that, 30 years on, the world is still facing an inability to confront the truth. “There’s a whole load of people that think climate change isn’t real, and in the meantime you’ve got a million young people marching around saying, ‘This is our future – for fuck’s sake take it seriously.’” The week we meet, 16-year-old climate activist Greta Thunberg has addressed EU politicians in Brussels. “It’s awful that it’s being left to the kids to speak up,” he says. “Our generation – we’re not covering ourselves in glory, are we?”

Harris now lives in the US, but we meet in a London hotel. As an actor he couldn’t be more different from his father – the notorious Richard Harris. While Richard was famous for his sound and fury, Jared is all about restraint and nuance. When his characters emote, they tend to do so with a barely perceptible twitch, the tiniest change in tone, a flush of the cheeks. He is brilliant at playing men who appear to have it all but are struggling inwardly – often silently.

Although he identifies as Irish (through his father, a militant republican) and Welsh (his mother), he is now best known for playing characters defined by their Englishness – cut-glass accents, privileged, painfully restrained. But as a young actor he found it impossible to play these parts. “When I was at Central drama school I was failing so miserably to play British aristocratic parts that the principal took me for a personal session. At one point he had me lying on top of a piano, and there were all these different exercises to try to loosen this block I had in my mind. And he said, ‘Jared, maybe you’re just going to have to resign yourself to not being able to play these parts.’”

Why does he think he had that block? “You’re so conscious of class growing up in Britain, and suspicious of that world and not feeling you belong to it.” But wasn’t he surrounded by posh actorly types when he was growing up? “No. My father had a massive mistrust of that world. The closest I would have got to that would have been through Rex.”

Facebook Twitter Pinterest Explosive truths … Harris and Emily Watson in Chernobyl. Photograph: Liam Daniel/Sky/HBO

Harris is referring to the actor Rex Harrison, the second husband of his mother, Elizabeth Rees-Williams. It seems she was just as formidable as his father. After divorcing Harrison, she went on to marry Peter Aitken (whom she refers to as “The Unmentionable”) and then his cousin, the Rev Jonathan Aitken, the former politician who served a prison sentence for perjury. “My mum has got a taste for very powerful men. She went from Dad to Rex Harrison and now she’s married to Jonathan and none of them are shrinking violets, and she holds her own against all of them.”

His well-to-do maternal side (his grandfather was the 1st Baron Ogmore) were appalled when they heard Elizabeth wanted to marry his father. “My grandmother ran down the corridor screaming, ‘No no no no!’”

It was his father who was known as the hellraiser, but Harris says that sobriquet could just as easily have been applied to his mother. “She was like a rock star. She was as much of that huge high-wattage personality as my father was. She’d had three kids by the time she was 25, and once their marriage broke up she decided she was going to live as wild a life as he did.”

Facebook Twitter Pinterest ‘She was like a rock star’ … parents Richard Harris and Elizabeth Rees-Williams. Photograph: Keystone Press/Alamy Stock Photo/Alamy Stock Photo

He remembers how she would turn up at his boarding school for visiting days, always late, always gorgeous in a giant hat and mini skirt. “The other boys would sit there and say why can’t your mother show up on time because their parents would turn up early and they couldn’t see the latest fashion she was wearing.”

Richard Harris was famous for lost weekends – or weeks – when he would go out for a pint of milk and end up bingeing on drink and drugs. In 1978, he gave up drugs after almost dying from a cocaine overdose, and flushed $6,000 worth of the drug down the toilet.

Harris says Richard was a great father – loving, caring, sharing. While the hellraiser reputation was deserved, he says it was also used to generate publicity. “He knew it was a story that would run and run, so he fed into it. To his detriment. There were times when he wanted to be taken seriously as an actor, and it was harder to do that if your reputation was as a mad, hard-living, hard-drinking Irishman who doesn’t give a shit about his career. And he really did. He cared about it massively. So did Peter O’Toole, so did all those guys.

“There was nothing they cared about more when they were researching a part. They were like monks about it. When they had time off or were on a film set and there were big weeks between what they were doing, they would live crazy lives, but, when it came to the work, they were dedicated to it.”

Harris was not close to Rex Harrison, the actor best known for My Fair Lady and Dr Dolittle. “He fell in love with my mother and we were just a package deal that came along with her. He wasn’t demeaning or cruel; he just wasn’t interested in kids. When you interacted with him, you did so as an adult. He wasn’t interested in your world. To give Rex his due, he was one of the finest light comedians ever.”

I learnt a lot about storytelling from listening to Dad constantly reinventing his stories

He tells a story about storytelling that sums up the difference between his father and Harrison. “You’d be sitting at a lunch table and Rex would start to tell a story, and suddenly he could have lost the audience because the subject’s moved on, but he wouldn’t move on. He would finish telling his story, and he wouldn’t notice if people were paying attention or not. Whereas my dad would tell a story and notice people paying attention at certain parts, and he’d be like, ‘Oh, you like this part’, so he’d embellish it. I learnt a lot about storytelling from listening to Dad constantly reinventing his stories.”

Harris may not have the presence of his father. Nor is he an obvious leading man. He is gap-toothed and speaks with a slight lisp. But there is something extremely attractive about him. He is at ease with himself and has a generous, life-affirming laugh. You sense he knows how to make other people feel good about themselves.

It’s not surprising that he has been involved with so many high-profile women over the years – he dated Raquel Welch’s daughter Tahnee for five years, was married to Emilia Fox for four years, and wed his third wife, TV host Allegra Riggio, six years ago. When he falls for somebody, he falls big. Before proposing to Fox, he filled their entire home with flowers. When he and Riggio married, she wore angel wings with her dress. He smiles when I suggest he’s an incurable romantic. “Yes, I think that’s probably true.”

Facebook Twitter Pinterest Quiet dignity … Harris as George VI with Claire Foy as Elizabeth in The Crown. Photograph: Alex Bailey/AP

He was a quiet child, in awe of the extroverts around him. “I enjoyed those personalities, but I wasn’t one of them. I was very shy when I was growing up.” His parents predicted he would become a lawyer or academic.

Harris, aged 57, graduated from university in the US and was 25 by the time he went to drama school in London. As a youngster he was obsessed with the American independent movies of the 70s. He hoped that one day he would be cast in similar films. He did go on to appear in US indy movies such as Mary Harron’s I Shot Andy Warhol (playing Warhol) and The Notorious Betty Paige, but his best work has been done for TV.

He says there’s a simple reason for that – it’s where the good work is being done. “I grew up loving movies like Dog Day Afternoon, The Conversation, The French Connection, Coming Home – amazing films, personal stories for the directors, and that has largely disappeared. That level of complexity of storytelling, nuance of character, is available to people in television now largely because the studios and the big feature films have given up on trying to attract adults. They are after a much younger core audience. They’ve surrendered that market to the TV.”

What work is he most proud of? “I’d normally say my last job.” You’re not getting away with that, I say – choose between Mad Men and The Crown. “Oh God … that’s really hard … I .., I think that … I’d throw The Terror in there. I thought that was really remarkable … er… erm …” He’s in a torment of indecision. I’m going to have to hurry you, I say. “Erm … probably … I’d take Mad Men. It’s really difficult to answer. I learnt something from Mad Men, whereas I’m less curious about the English thing because you lived it, you grew up with it; it’s not so much of a learning curve. But both are brilliantly well done, and very smart writing. It’s no accident that you’re putting them on the same level.” He wipes his brow.

I pretty much disavow Lost in Space because they dubbed half my performance. Watching it is an abomination

And the work he’s least proud of? He relaxes at the very question that makes many actors tense up. “I pretty much will disavow Lost in Space because for whatever fucking reason they decided to dub half my performance with some other person, and watching it is an abomination. You think how drunk were they when they decided that the audience wouldn’t notice it’s two completely different people even within one line.”

I ask him if he’s surprised that success had come relatively late in life. For the first time, he sounds slightly defensive. “Well, I was 28 when I got out of drama school. I started pretty late, so, given that, I’ve not done too badly.”

But it feels as if you’re more in demand than you have ever been, I say. He nods, and says that, strangely, he may have been helped by Daniel Day-Lewis quitting the profession. “He was supposed to do the part in Chernobyl. Thank God he retired!” And he starts to list the parts he has played that were turned down by Day-Lewis. “He was offered Moriarty in Sherlock Holmes, too. They said, ‘I hope you won’t be upset.’ I said, ‘No, that’s pretty good company to keep.’ Everything gets offered to him first. Everything! Hehehe!” He laughs, long and warm. “I was really lucky he decided to retire.”

• Chernobyl starts on 7 May on Sky Atlantic.

