A Very British Scandal’s Claire Foy says the Duchess "would have hated" her

Foy went on to joke that she was "so low class", before mimicking Margaret: "Look at her! Look at her!

"I love her even more, the fact that she would hate me."

But Phelps has a sneaking suspicion that the Duchess would have approved of Foy.

“I think she would have probably been on the outside incredibly snotty and very, very scathing, but secretly delighted," she said. "And she would have gone home and she would have cut out everything to do with Claire Foy and put it in a special scrapbook.”

Speaking about the tempestuous relationship between Margaret and her former husband, Ian Campbell, the Duke of Argyll, Foy added: “I think that people, without being self-aware, see in someone else the damage that they also find familiar in themselves, and you see it very clearly in this programme.

"You see two people who are equally as damaged as the other meeting each other and going, ‘I find you really attractive, but I can’t put my finger on why that is.’ And then they embark on this relationship. And watching any relationship break down is deeply sad but also really fascinating from the outside because you always want to know where it went wrong. At what point was there no return?

"And I think what’s interesting about the end of their relationship is it plays out in the public domain. The end of their relationship is not those two in a room being able to look each other in the eye and go, 'At one point we loved each other. What happened?' It was just messy and so underhand and cruel, and the only way she could reach him was via the newspapers, and that’s how they basically communicated, it felt like."

A Very British Scandal is available to watch now on BBC iPlayer. The series is also airing on consecutive nights across BBC One. If you’re looking for more to watch, check out our TV Guide. Visit our Drama hub for all the latest news.