Gillian Anderson set 'boundaries' with boyfriend Peter Morgan on The Crown

Gillian Anderson set “very clear boundaries” whilst working with her partner, Peter Morgan, on the set of ‘The Crown’.

The 52-year-old actress stars as former UK prime minister Margaret Thatcher in the upcoming fourth season of the Netflix hit series, which was created and principally written by her boyfriend, Peter.

And for the “benefit of the relationship”, Gillian and Peter made sure to set boundaries between them, which stopped them from criticizing one another’s work whilst on set.

Speaking to the December issue of Harper’s Bazaar magazine, she said: “For our own sanity, and actually for the benefit of the relationship, we had very clear boundaries. I am not going to comment on the script, but you are not allowed to comment on the performance!”

Gillian also insisted she had to cast away her own “opinions” of Margaret Thatcher and her “actions” before taking on the role.

She added: “I had to get to a point where it’s nothing to do with my opinions of her policies, of her actions. It is only about her as a human being and her motivation as a politician and as a mother.”

But thankfully, after decades in the business, Gillian - who has 26-year-old daughter Piper with her ex-husband Clyde Klotz, as well as Oscar, 14, and Felix, 12, with former partner Mark Griffiths - has learned how to “compartmentalize” her own life to keep it separate from her work.

She explained: “I’m pretty good at compartmentalizing in my life, period. I think I learned that quite young, being a young mother, in a really intense TV series where it was either full on on-set, or I was in my trailer having to shut the door and no longer be that person but be mum.”

And whilst she plays a politician in ‘The Crown’ - which is a dramatic re-telling of the life of Queen Elizabeth II and the royal family - Gillian says she doesn’t feel the need to publicly comment on politics “on a regular basis”, because that’s not her “world”.

She said: “I feel like I have an opportunity as somebody in the public eye to draw attention to things, but I don’t comment, I don’t offer my opinion on social media on a regular basis, because it’s not my world. I’m an actor, I’m not a politician, I’m not a social worker.”

The full interview with Gillian Anderson is available in the December issue of Harper’s Bazaar, which is on sale from November 5.