King Charles and Queen Camilla are yet to confirm whether they will attend the wedding of the Duke of Westminster, Hugh Grosvenor, and Olivia Henson, despite the event being just three weeks away.

The couple snubbed the duke’s sister’s wedding over a disagreement about where Camilla would sit (Image: AFP via Getty Images)

King Charles and Queen Camilla could be set to miss the “wedding of the year” after reportedly failing to respond to an invite with the event just three weeks away.

The pair are yet to put in writing whether or not they will attend the big day between the Duke of Westminster, Hugh Grosvenor, and his bride-to-be Olivia Henson, according to reports. The late decision has caused speculation about tensions between the groups after the King and Queen turned down an invitation to the duke’s sister Lady Tamara Grosvenor’s wedding back in 2004.

Lady Grosvenor married Edward van Custem, a godson of His Majesty, at Chester Cathedral – the same location as this year’s wedding next month. It came after Camilla, who went under her former surname Parker Bowles at the time, was told she wouldn’t be able to sit with a then Prince Charles and would need to sit several rows back and arrive separately.

It was because Queen Elizabeth and Prince Philip attended the ceremony along with Princes William and Harry. According to MailOnline’s royal correspondent Richard Eden, a source said: “Their Majesties have not forgotten what happened at the wedding of Hugh’s sister. There is still a lot of tension that exists.”

Speaking about the situation, royal author Sarah Bradford said the now Queen was so angry she told Charles the status quo was no longer acceptable. At the time, an insider explained: “Her Majesty is a stickler for protocol. It would be inappropriate for Mrs Parker Bowles to sit beside Prince Charles since she has no official standing.”

King Charles and Queen Camilla could be set to miss the “wedding of the year” (Image: Getty Images)

Tensions were heightened by claims that Emilie van Cutsem, the groom’s mother, and Camilla fell out after allegedly criticising the behaviour of each other’s children.

Charles ultimately excused himself from the event with just days to go, saying he had to visit Warminster barracks to meet the families of soldiers serving in Iraq, while his partner was “otherwise engaged”.

Charles and Camilla have not yet responded to the invite (Image: Getty Images)

The Duke and Duchess of Sussex have already been excluded from next month’s wedding, despite Hugh reportedly being godfather to their son Prince Archie.

It’s believed the duke thinks inviting the pair, who reportedly received a save the date email in error, could cause tensions with the Royal Family.

A source close to the Sussexes later said: “Harry called Hugh and said it would be too awkward if he and Meghan Markle attended, so he made his apologies and Hugh understood.”

The Prince and Princess of Wales and their elder son, Prince George, who is Hugh’s godson, are invited to the wedding. However, Catherine is not expected to attend because she is undergoing cancer treatment. A spokesman from Buckingham Palace declined to comment.