Josh O'Connor first found fame in ITV drama The Durrells, but has made a name for himself in a series of smaller character studies, including new film Only You. He talks to Laura Harding about his interest in challenging conventional ideas of masculinity and how that applies to his upcoming role in The Crown.

Josh O'Connor has had such a busy day he barely knows if he is coming or going.

He's just wrapped up a photoshoot for the highly anticipated upcoming series of The Crown, in which he plays the Prince of Wales, he's promoting his new film Only You, and he's en route to a meeting about another film.

To say he's busy would be an understatement.

"I literally don't know what I'm talking about," he jokes good-naturedly. "I'm really confused!"

But this proves far from the case. Ever since he first found fame in the ITV drama The Durrells, as aspiring writer Lawrence, the 29-year-old from Cheltenham has made a name for himself in thoughtful and varied projects.

He starred as repressed farmer Johnny Saxby in the critically-acclaimed movie God's Own Country, played Maurius Pontmercy in the BBC's Les Miserables, and his latest project is the romantic drama Only You, about a couple who start a passionate relationship after a chance meeting but struggle to navigate a battle with infertility.

"When I first read it I didn't think it was a film about infertility," O'Connor says.

"I think it's a love story, about two people who fall in love very quickly and then are presented with a problem.

"The younger person, who is a male figure in that relationship, is the one that presents the idea of having children and I found that really fascinating.

"A year before I had played Johnny Saxby in God's Own Country, which felt very different, and this was a role that had so many likenesses in many ways to myself, and I thought that's a real challenge, the idea of playing someone whose idea of marriage and being in a couple is very much that you find someone, you fall in love and you're with that person for the rest of your life.

"You have kids, you buy a house and it's this perfect formula. But then watching someone with that perfect idea crumble because stuff doesn't go like that in real life, s*** goes wrong."

He pauses. "When I say I took the role because I thought it would be interesting to play something close to myself, now I look at Jake as a character and I don't see anything like me at all. I don't see any resemblance at all."

What he does see is a recurring pattern throughout his career, of characters that represent different elements of modern manhood.

"I haven't been acting for that long, but in my small, short career, I've been able to do a range of different things and played a range of different characters, and that is what I'm ultimately fighting for.

"But if there is a through line, if I've curated the work that I do, it's a sort of 'notes on masculinity' and challenging masculinity and what that means, what masculinity means.

"Jake [his character in Only You] is a perfect example of that.

"He is the emotional one, he is emotionally articulate and Laia's character [Elena, played by Laia Costa] is far less articulate with her emotions and her feelings, and that is totally different to both Prince Charles and Johnny Saxby.

"Generally speaking we know men as being closed off or not able to engage, and it's really nice playing a male character who isn't and who wants to engage."

O'Connor made headlines last summer when it was announced he would play the heir to the throne when the third series of The Crown launches on Netflix, with newly minted Oscar winner Olivia Colman taking over the role of the Queen from Claire Foy.

"At the moment, masculinity seems to be a huge theme for me, partly because for men it's a huge challenge right now in society.

"Our leaders are archaic masculine figures, in so far as they are aggressively old fashioned in their masculinity, people like Trump, potentially Boris Johnson.

"I don't know what masculinity means and I guess that is what my interest is.

"I would describe Johnny [his character in God's Own Country] as a negative form of masculinity, where he drinks and numbs any kind of emotion and doesn't engage emotionally with someone on that level.

"Jake is someone who fully engages. and someone like Prince Charles is someone who engages with it to a point, but publicly can't really engage with it. Then there is someone like Lawrence Durrell, who is comically engaged with it all of his life."

The anticipation that surrounds the arrival of The Crown, expected later this year, has been a shock to O'Connor, who has thus far been able to work without the prying eyes of fans and the interference of long lens photographers.

This time pictures of filming have been splashed all over newspapers and websites.

"It's really weird," he says. "In some ways I wasn't expecting it, which is bizarre because I probably should have.

"I was really excited to play the character of Prince Charles and I just kept seeing it as a character and not as the real person, so it's a really strange thing because obviously there is a lot of buzz about it and people are excited.

"I'm really pleased, it's a piece of work that I'm really proud of. I'm really excited for people to see it."

He worked closely with Colman on the big budget series and describes the actress as "a total hero".

"She somehow manages to balance having kids and having a family life and also going off and winning a blooming Oscar and doing everything else - and she's the best.

"I was going to say the best Queen Elizabeth ever, but that would be harsh on Claire Foy, she's an amazing Queen and she follows on from Claire Foy so brilliantly."

When he was cast he made a gag that he had "the ears for the part," and now he laughs at the memory.

"When I was at school I was embarrassed by them and I wanted to pin them back and now it's like, 'Thank God I didn't!'

"Hopefully I would have been considered for the role regardless, but it certainly helped.

"And the way I see it, it just saved The Crown production on some prosthetics."

"They were struggling for money," he says with a laugh. "They were scraping around, so I definitely saved it. Everyone can thank me for that."

Only You is in cinemas now.