The ‘Poldark’ star has signed up to star opposite Kristen Stewart – who will play the Princess of Wales, who was titled Lady Diana Spencer before her marriage to the heir to the throne – in Pablo Larrain’s biopic, which has recently moved filming from Germany to the UK.

‘Spencer’ – which also stars Timothy Spall, Sally Hawkins, and Sean Harris – focuses on one weekend in the life of Princess Diana in 1991, as she spends the Christmas holiday with the royal family at the Sandringham estate in Norfolk, and decides to leave her marriage to Prince Charles.

The film was written by Steven Knight, and is being produced by Juan de Dios Larraín for Fabula Films, Jonas Dornbach and Janine Jackowski for Komplizen Film, and Paul Webster for Shoebox Films.

The producers previously said in a joint statement: “We are extremely grateful for the support of our distributors worldwide, our partners and funders who have shown tremendous commitment to us in these extraordinary times.

“With Kristen Stewart, Steven Knight and the rest of our fantastic team both in front and behind the camera we are bringing ‘Spencer’ to the world. It is an independently produced film made for the big screen about an iconic woman’s own declaration of independence. We couldn’t be more excited!”

Executive producers are Tom Quinn, Jeff Deutchman and Christina Zisa for NEON and Michael Bloom, Maria Zuckerman and Ryan Heller for Topic Studios.

Charles and Diana separated in 1992 after 11 years of marriage and divorced in 1996. The following year, the princess – who had sons Prince William and Prince Harry with her ex-husband – died in a car crash in Paris, France.