Rumours have been flying over a "feud" between Kate Middleton and her sister-in-law Meghan Markle, and now royal biographer Christopher Wilson has added fuel to the fire.

The Duchesses are both due to spend Christmas at Sandringham with the rest of the royal family, and this will be tough for Kate because she'd much rather spend it with her mum, dad and siblings.

Sandringham is also quite formal and involves black tie dinners - plus the Queen will be there, so you can't really let loose.

Chrstopher told New! magazine : "Kate's a homebody and loves being with her own immediate family at Christmas - off-duty and relaxed.

"Sandringham Christmases can be an ordeal, even for those born royal - and generally those who've married into the family often can't wait to get away".

He also referenced the whispers of a spat between Meghan and Kate.

"As with many seasonal family gatherings, there can be undercurrents and the publicity over the Meghan clash won't make things any easier between the girls," he said.

Kate and William have had their share of Christmas drama over the years.

In 2006, the Duchess of Cambridge was left "tearful" after the prince called her to cancel his plans to visit her family.

A source told biographer Katie Nicholl: "At the last minute William had a change of heart and decided to stay with his own family instead," so he "informed a tearful Kate during a late-night conversation on Boxing Day."

She forgave him in the end though, and the happily married couple were recently seen hosting a Christmas party at Kensington Palace.

The festive celebration was in honour of families and children of deployed personnel from RAF Coningsby and RAF Marham who served in Cyprus.