Ruth Wilson has said that she doesn’t intend to get married because she doesn’t “believe in institutions”.

The His Dark Materials star is in a long-term relationship with an American writer, who she has never named, but has no intentions of getting married.

Speaking to The Guardian, Wilson said: “I believe in connections; I’ve got a very strong relationship, and have had for a number of years.

“I believe the value of having someone in your life who understands you and sees you is enormous. And I’m so glad I have it. But I don’t believe in institutions.”

She continued: “I feel slightly restricted by having to conform to someone else’s idea of what a relationship is, or where you should be at this time in your life. It feels dogmatic to me.”

Wilson’s grandfather was a polygamist – she famously played her own grandmother in the BBC historical drama series Mrs Wilson.

Discussing a time a journalist suggested to Wilson that she might not want to get married because polygamy runs in her family, she sarcastically said: “Yeah, it’s genetics. You know, my grandfather died before I was even born, and my parents have a great marriage. It must have skipped a generation.”

Elsewhere in the interview, Wilson said that while she did think about having kids, she was unsure if it was “possible” while working as an actor.

“I think about having children, and I don’t know how I could do the career I do with a child. I do question how that’s possible. The travel. The amount of mind time it takes me. I’m not sure how I could do it.

“I think it’s a myth that you can do it all and do it all easily. It’s just not the case – and shouldn’t be, probably. It’s a mad world, a wonderful world, and I love it. But it makes those other choices in life difficult.”

She added: “I’m a commitment-phobe generally. Most actors are, probably.”