Kate's secret advisor CAROLE MIDDLETON SAVES THE ROYALS

How she rekindled her daughter’s romance when it all looked lost

- Judy Kean

Catherine, Duchess of Cambridge has long been described as the royal family’s MVP, with one commentator now going as far to say that the British monarchy couldn’t survive without her.

And for the part Kate plays in keeping the royals stable and popular, we have her mother, Carole Middleton, to thank.

Carole, 67, played a critical role in Kate’s relationship with her husband Prince William, and if not for her guidance, things could have been very different, says royal biographer Tina Brown.

Describing Kate’s mum as “Coach Carole” in her new book The Palace Papers: Inside the House of Windsor – the Truth and the Turmoil, Tina says Kate, 40, required “a lot of care and strategy to end up married to William”, much of it driven by her mother, who helped her to avoid missteps that could have spelled the end of the relationship.

But thankfully, it all turned out for the best in the end, which is just as well for the royal family, says Tina. “They would, I think, crumble at the moment without her, because she’s the only modern, beautiful woman who’s well-educated, substantial in herself, who’s actually wanting to commit herself to the rigours of this institution. Not many young women could do that.

“In 2011, the question mark over Kate Middleton was whether a girl of such unexalted origins could successfully evolve into a future queen. Now the only question is how the House of Windsor would survive without her.”