Prince Harry and Meghan Markle have been left off the guest list of a high-society wedding amid the fallout of their rift with the Royal Family.

In June, Hugh Grosvenor, the Duke of Westminster and Olivia Henson, 32, will get married but – despite Grosvenor being a close friend of Harry’s – the Duke is not on the guest list.

The royal affair will take place on June 7 at Chester Cathedral, in northwest England. According to The Sunday Times, Prince William, Princess Kate, King Charles and Queen Camilla will attend the service.

It’s thought that Grosvenor didn’t invite Meghan and Harry to avoid a family clash between Prince Harry and his brother.

A friend told The Sunday Times: “It’s incredibly sad it has come to this. Hugh is one of very few close friends of William and Harry’s who has maintained strong bonds and a line of communication with both.

“He wishes they could put their heads together and patch things up, but realizes it’s unlikely to happen before the wedding. He wanted to avoid anything overshadowing the day, especially for Olivia and doesn’t want any awkwardness.”

A spokesperson for Grosvenor told PEOPLE: “We are not in a position to comment on the guest list.”