Poots is also required to sing (of rosebuds rather than fleshpots) in her role as Blanche Ingram in the forthcoming film version of Jane Eyre, where she and Michael Fassbender's Mr. Rochester perform operetta duets, and again struggled, at times, to keep a straight face.

"At least Michael and I will always have a duet up our sleeves if we need it, And you never know, And She Never Told Her Love could become a classic."

She and Fassbender had acted together in the 2010 action movie Centurion, filming in Inverness in freezing February, where the delicate-looking teenager loved roughing it with the almost exclusively male cast – one of whom got frostbite – going for a curry after filming, "playing a hag in hut, with a designer scar".

Jane Eyre, by contrast, promises a lavish depiction of Charlotte Bronte's gothic romance, with costumers designed by Michael O'Connor (who won an Oscar for The Duchess). Poots loved the sculptural gowns and their no-prisoners underpinnings, "though you don't ever go to the loo. Ever. I so envied Michael has zip".





It was hard, moreover, to look the elegant county beauty while perched on her perpetually flatulent horse: "I'd be sitting there, trying to look ladylike, and the horse was farting away."

Her ability to look ravishing in bonnet (or anything, actually), as she did playing Fanny, the niece of Jane Austen, in the television drama Miss Austen Regrets, must have helped her win the part of Jane's pretty conniving rival; not to mention her charming tendency to blush like a peony at any opportunity.

The more the director of Jane Eyre, Cary Fukunaga asked her about her pink face on their first meeting )she had been filming Bouquet of Barbed Wire outdoors), the redder she went with self-consciousness. "I'm sure he wasn't thinking, 'Bloody hell, what's wrong with this girl's face?"