Not a one-dimensional portrait: Gillian Anderson on playing Margaret Thatcher on 'The Crown'

Actor Gillian Anderson, who is set to play Margaret Thatcher on the royal period drama "The Crown", says fans will be surprised to see an emotional side to the former British Prime Minister in the upcoming season.

The fourth chapter of the critically-acclaimed Netflix series will mark the return of Oscar winner Olivia Colman as UK monarch Queen Elizabeth II, Tobias Menzies as Prince Philip and Helena Bonham Carter as Princess Margaret.

According to Anderson, the show paints a "whole portrait" of Thatcher, a complex woman who defined an era, just like her contemporary Queen Elizabeth II.

"We certainly see another side of Thatcher that has more of an emotional life than perhaps has been seen before. For instance, in terms of the episodes where her son goes missing.

"That is grounded, well-founded and well-documented emotion that she was experiencing at that time, so it doesn't feel like it's out of order in a way. It's a whole portrait. It's not a one-dimensional portrait," she told RadioTimes.com.

The 52-year-old actor said there won't be any "fiery scenes" between Thatcher and the monarch, who shared a complicated relationship.

"There are a few audiences where they push each other's buttons. They certainly don't raise their voices, but they definitely push each other's buttons," she added.

Anderson, best known for her work in the American sci-fi drama "The X-Files" and British comedy-drama television series "Sex Education", said finding the distinctive voice of the former UK PM was the most important aspect of playing the role.

"First and foremost, finding her voice seemed to be the first physical way in. And once feeling comfortable there, the other elements of it end up feeling like cherries on top. You can have all of the physical accoutrements that you want for Thatcher, but if you don't have the voice then it's not going to fly," she said.

Also joining the cast in season four is newcomer Emma Corrin who will play Princess Diana.

Created by Peter Morgan, the new season of "The Crown" is slated to start streaming from November 15.