The Prince of Wales was a great support to Prince Harry and wife Meghan Markle during their tough first few months of marriage together, according to a filmmaker who got to know him well.

Prince Charles advised his youngest son to ignore the critics and 'soldier on', claims John Bridcut, who spent a year with the heir to the throne filming a documentary to mark his 70th birthday last November.

Describing the heir to the throne as a “caring, kind and sensitive” soul - who has a close friendship with his sons, Bridcut claims the prince drew on his experience of his troubled marriage to Diana, Princess of Wales, to become a solid supporter of the the Duke And Duchess Of Sussex.

The filmmaker conducted in-depth interviews with the Prince, his wife, the Duchess of Cornwall, and Princes William and Harry for ‘Prince Charles at 70’ which premieres on PBS in the US tonight.

“There is a close relationship between father and son and I'm aware that he gets along very well with both the daughters-in-law,” explained Bridcut. “He is naturally a warm person.”

Asked about the advice he passed to Harry and Meghan about their recent dramas involving the Markle family, Bridcut said: “His approach would be that you just carry on doing the job. He wouldn’t have added to that. His attitude would be that some of the attacks he would feel were unfair.