Princess Diana 'saved' the Royal Family, Sir Richard Branson says

Princess Diana helped to "save" the Royal Family and stop Britain from becoming a republic, according to Sir Richard Branson.

The English entrepreneur, who was a friend of Diana's, has said the 20th anniversary of her death should be treated as an opportunity to celebrate her legacy.

He explained: "She's had two magnificent kids who have done fantastic things and will continue to do great things. And I would say that actually has saved the Royal Family.

"There was a time when Britain could have easily become a republic, a few years before her death.

"But now the thought of that has gone completely and I think that's largely to due to her two wonderful children."

Sir Richard first met Diana when she stayed on Necker Island, his private island paradise, with a young Prince William and Prince Harry.

Their regular tennis matches were often a time when she would talk about the more difficult aspects of her life in the public eye.

He said: "We used to play tennis together - she won of course. We'd obviously talk afterwards, she'd had a lot of struggles, and particularly in the last two or three years of her life, she would open up about them.

"She put on a very strong face about it and just got on with her life."

Sir Richard also recalled Diana's sense of fun - and how she had "everybody in fits of laughter" during a Virgin Atlantic flight.

"She went into the cockpit with Prince William on her knee and she got on the loudspeaker to everybody in the plane and said 'if you look out to the left you will see granny's house' as we flew over Windsor Castle," he said.

Comedian Ruby Wax, who was also a friend of the Princess, recalls being totally star-struck the first time she met Diana.

She said: "As she shook my hand I went into a plie position, and I couldn't pull out. I froze, with my legs in the second position in ballet as we call it."

Wax has recently worked with Prince William and Prince Harry on their Heads Together campaign.

She believes that, like their mother, they are shining a light on causes that traditionally have been surrounded by stigma.

"Mental health has such bad implications, so I would rather that they're the representatives than someone who is on screen. These are clean, healthy, smart, sexy boys," Wax added.

On Wednesday, the Duke and Duchess of Cambridge and Prince Harry will meet representatives from some of the charities that their mother supported in the sunken garden at Kensington Palace.

This year the garden has been given a special white theme in memory of Diana, who often used to stop and talk to the gardeners working on the grounds.

Thursday marks the 20th anniversary of the day Diana died in a car accident in Paris. She was 36 years old.

:: Watch Sky News' documentary Diana: The People's Princess at 8pm tonight.