‘We rot. Don’t we?’

Joanna Lumley and Sister Elizabeth Obbard are seated at the front of the church. Lumley is perched elegantly on the edge of her chair; Sister Elizabeth settles deep into hers, submerged under folds of habit. They are talking in front of an audience at the Carmelite church in Kensington, west London, about life as a nun. And Sister Elizabeth is being wonderfully honest. ‘The first six months were dreadful,’ she says. This was in the 1960s, when religious sisters did hard, physical work that was ‘supposed to make you humble’. Did it make her humble, asks Lumley. ‘No,’ says Sister Elizabeth, who is meek but steely. ‘It made me angry.’

The evening has been organised by Grange Park Opera, in advance of its production of Les Carmélites, a spine-chilling opera about the French Revolution that culminates in the execution of 16 nuns. The connection to Lumley is that her husband, Stephen Barlow, is conducting.

Lumley says she wanted the evening to illustrate how ‘ordinary ordinary’ a nun could be — ‘kindly, well read, easy to talk to’. I meet her a few weeks later. In between she was in New York, filming The Wolf of Wall Street, in which she kisses Leonardo di Caprio. The paparazzi took lots of pictures. ‘It’s the sound, tsk, tsk, tsk, click, of the camera that’s horrible. It’s distracting.’ The kiss, she says, irritated, had to be done ‘again and again and again’.

Lumley (who is 66) is, of course, charming and courteous and lovely. By the end of our meeting, though, I worry things have turned a bit bleak.

The life of a nun is not entirely new to her: she was educated at an Anglo-Catholic convent in Sussex. She loved it, she says, and kept in touch with all her teachers.