“You can’t play this story without addressing sexuality in this particular society in this time, the masculinity of the men, the femininity of the women, the vulnerability of prepubescent girls.

When he was in Spooks, Armitage famously gained first-hand experience of waterboarding in preparation for a torture scene.

He says this sort of understanding is essential to his approach to acting.

I ask him if, in the era of tabloid witch hunts, those in the public eye live with a fear that one day they’ll wake up to find that they’ve become the story, and whether this means having to censor parts of his character in public all the time.

“I think if you’ve got stuff to hide, there’s a level of stress that people live with.

He’s bearded and dressed in thick shapeless trousers, heavy boots, and a rough collarless cotton shirt open at the neck to reveal a broad chest. Anyone who knew the 42 year-old only as the dwarf Thorin Oakenshield in The Hobbit films might have quite a shock.

Television viewers who associate him with double agent Lucas North in Spooks, nasty Guy of Gisborne in Robin Hood, or the character based on SAS man Andy Mc Nab in Sky One’s Strike Back would know different. Armitage is to play the tormented John Proctor in the playwright’s terrifying account of the 17th century Salem witch trials, in which Proctor’s adulterous relationship with a young woman sparks a vengeful chain of events that leads to the deaths of many.How does Armitage feel to be up against that performance? And I think there are some monumental performances in it.But I think there’s something about witnessing this play in the round - the theatre is a sort of bowl shape like a crucible - with the audience observing themselves across the room at times, that is the most exciting aspect of this.” Day-Lewis prepared for the role by building his character’s house himself with 17th-century tools.He then worked in musical theatre before going to drama school in London and joining the RSC.But he says his experience of trying to win bigger roles convinced him to alter course.“You fight for certain roles and you realise they’re being filled by television and film actors, because theatre is constantly fighting for survival and they need names and faces and ticket sales.