Gillian Anderson is the guest on this week's edition of The South Bank Show, revealing how she got into character for Netflix's The Crown – and the challenges she encountered.

Anderson plays Prime Minister Margaret Thatcher in the drama's recently-launched fourth season and, in a clip debuting exclusively on, reveals how she felt nervous about debuting her "Thatcher voice" for the first time.

Speaking to interviewer Melvyn Bragg on the Sky Arts series, she reveals how "really not wanting to get it wrong" led to "a lot of overthinking" and how it eventually required a "kick up the rear" to convince her to cut loose.

Anderson previously told Variety that she had had to put all “preconceptions and opinions” to one side to play Thatcher.

“One of the things that I have found in playing historical characters is to put aside all preconceptions and opinions, particularly in regards to Margaret Thatcher,” she said.

“Because in making choices within scenes or within the arc of the series, one has to have a deep understanding of how they arrived to those decisions, how the character was able to take the actions and develop those attitudes and policies, in [Thatcher’s] case.”

Gillian Anderson as Margaret Thatcher in The Crown season 4
Gillian Anderson as Margaret Thatcher in The Crown season 4 (Netflix) Netflix

The Crown creator Peter Morgan also recently told Netflix Queue the conflict between Thatcher and the Queen (played in the series by Olivia Colman) is "at the heart" of its latest season.

“On the face of it, Elizabeth and Margaret should get on,” added Colman. “They are the same age, have the same drive, the same devotion to their fathers, the same work ethic.

“Yet they don’t. It’s not the beautiful friendship that the queen hopes it will be at the beginning.”

Want to know more about the Queen and Thatcher's relationship, Denis Thatcher, Carol Thatcher or how Mark Thatcher went missing? Read our suite of content across

Gillian Anderson will appear on The South Bank Show tomorrow (Sunday 22nd November) at 10:45pm on Sky Arts, Freeview 11 – find something to watch tonight with our TV Guide