Kate Middleton might miss Princess Eugenie's wedding because of sister Pippa

Princess Eugenie’s wedding list will include plenty of royal and celebrity names, but there could be one major no-show on the day: Kate Middleton.

According to The Express, the Duchess of Cambridge, 36, could face a tricky calendar clash when her cousin-in-law’s Windsor Castle nuptials roll around. 

The newspaper reports Princess Eugenie’s wedding is likely to fall around the time Catherine’s sister Pippa, 34, is due to give birth to her first child.

From this, The Express estimates an October due date.

Princess Eugenie, 28, will wed longtime boyfriend Jack Brooksbank on October 12 at St George’s Chapel, the same venue where Prince Harry married Meghan Markle back in May.

RELATED: Pippa Middleton wears baby blue for nephew Prince Louis' christening

Given how close the Middleton sisters are - Pippa was seen driving into Kensington Palace the day after Prince Louis was born in April - it seems obvious where the Duchess’ priorities would lie.

While the wedding is sure to be a star-studded affair, with the likes of Robbie Williams, David Beckham and countless royals expected to attend, Catherine mightn’t be the only no-show.

Apparently, it all comes down to family tensions: namely, the 97-year-old’s famously icy relationship with the mother of the bride, Sarah Ferguson.

"He made a supreme effort for Harry. I would be very surprised if he did go, because he is so estranged from Fergie,” the insider claimed. 

Ferguson alluded to the pair’s issues in a 2011 interview with Dr Phil in the wake of the royal scandal that erupted around her the previous year.

Discussing the incident - she was caught trying to sell access to the royals to an undercover reporter posing as an Indian businessman - she said Prince Philip had called her “idiotic”.

If Prince Philip does decide to attend his granddaughter’s wedding, whoever is in charge of the reception seating arrangement really has their work cut out for them...