Lydia Leonard will reportedly play Cherie Blair in the upcoming series of ‘The Crown’

The fifth season of 'The Crown' will see a new cast change for the major royal roles as it will shift to cover the 1990s, including the tragic death of Princess Diana - who will be played by Elizabeth Debicki - months after Blair took office in 1997.

Queen Elizabeth II will be portrayed by BAFTA-winning Imelda Staunton. ‘Game of Thrones’ actor Jonathan Pryce will play Prince Philip and Lesley Manville will be Princess Margaret.

Olivia Williams and Dominic West are Camilla Parker-Bowles - who is now known as the Duchess of Cornwall - and Prince Charles.

However, producers are still searching for a teenager to play Prince William.

A casting call from Netflix stated they were looking for: "A boy aged between 13 and 15 years old to play 13-year-old Prince William in the next series... talented, intelligent and sensitive boy who can rise to the challenge of playing this famous character alongside leading British acting talent."

Insiders claimed there is a struggle casting someone in the role because of the "harrowing" time in the prince's life, including the fall-out from Diana's controversial tell-all 'Panorama' interview with Martin Bashir, and the aftermath of her death in a Paris car crash.

A source told the Daily Mail newspaper's Eden Confidential column: “A lot of parents would think twice before letting their son appear in such a drama. It's going to be a harrowing role that will create a major backlash.”

However, Netflix told the publication there was no problem.

They said: “We are well into the process and all is well. Child casting in general just takes longer."