The Oscar and Bafta-nominated Cillian Murphy, a hot contender to win best actor awards for his portrayal of Robert Oppenheimer in Christopher Nolan’s film about the creator of the atom bomb, has revealed he would still happily return to the role of Peaky Blinders’s Thomas Shelby, on the small or the big screen, if the chance came his way.

“If there is more story to tell, and if Stephen Knight delivers a script like I know he can, then I will be there,” Murphy said. “I mean, if we want to watch 50-year-old Tommy Shelby, I will be there. Let’s do it.”

Talking to Lauren Laverne about the impact of success on his life on BBC Radio 4’s Desert Island Discs this weekend, the charismatic performer from Cork also explained his approach to playing Oppenheimer. He realised, he said, the portrayal “would be ultimately a synthesis of the script, all the stuff that I was absorbing of him, and then an element of yourself in it. And then you put it all in the mix and that becomes Chris’s version and my version of Oppenheimer.”

Murphy also confesses his reluctance to appear on the red carpet at public events, before his prominent role in the awards season. “I have struggled in the past,” he said. “But you can choose to enjoy it. You can make that alteration in your brain. Really, you would be an eejit not to enjoy it. Just go with it.”

Professionally, Murphy tells Laverne, his nerves are worse on a film set than on stage, where he started: “The distinction being that when you do a play, you retain control, in so far as, if it is a terrible night, you know tomorrow you can fix it. But in film, there is no fixing it.” He also finds the silence on a set before he delivers a line is intimidating, he added.

Murphy, 47, also discusses his early hopes of a career in music, something that almost came to pass when his band was offered a five-record deal.

But the parents of some of the band members objected and so Murphy moved on to acting, securing a role in Enda Walsh’s play Disco Pigs, before landing a career-altering part in Ken Loach’s 2006 Cannes Palme d’Or-winning film The Wind That Shakes the Barley. “It changed the way I approached work profoundly,” he said of Loach’s improvisational technique.

But the part that made him a household name, Shelby in Knight’s epic television series about Birmingham gangsters, did not fall into his lap, Murphy confessed: “I wasn’t the obvious choice physically. I don’t know if I convinced Stephen in the meeting, but apparently afterwards I sent him a text that said: ‘Remember, I am an actor.’ And I do believe that. I do think it is our duty as actors to transform to whatever the part demands.”