Princess Eugenie and Princess Beatrice’s seating arrangement at the Platinum Jubilee service of Thanksgiving St. Paul’s Cathedral left Prince Harry and Meghan Markle absolutely furious, according to royal commentator Richard Eden.

The Duke and Duchess of Sussex were said to be seething as they were prevented from switching seats by Prince Andrew's daughters, who didn't move from their designated seats in an orchestrated ploy to block any awkward photos with the couple.

Appearing on Palace Confidential, Eden discussed the seating arrangements at St. Paul's and how the two princesses didn't move from their seats to avoid an awkward photo opportunity with the Duke and Duchess.

Eden revealed that there was assigned seating, and that the princesses stayed put in their designated seats to avoid being photographed with Harry and Meghan.

The reason for this move became apparent when there was a procession to leave the cathedral, which meant that Harry and Meghan were far behind and had to wait for everyone else in their row to leave first so they couldn't be photographed.

This meant that they weren't in the same shots as Prince Charles or the Cambridges, and were nowhere near them.

Royal expert Richard Eden believes that the firm effectively threw royal protocol out the window by snubbing Prince Harry and Meghan Markle at the Queen's Platinum Jubilee celebrations.

Speaking on Palace Confidential, he said that everyone was intrigued by the seating plan at St Paul's Cathedral, which was genuinely fascinating.

Even though the royal family was very keen to make sure that Harry and Meghan were mentioned in the court circular, they were relegated to the second row and had to sit behind the Queen's cousins who come far down the line of precedence.

Both Prince Harry and Meghan were tucked away, and many royal experts suggest that this may be why they left the UK early, even before the Jubilee celebrations ended.

William refused to make any eye contact with his younger brother Prince Harry at St Paul's Cathedral, and the estranged brothers sat a few rows apart at the Platinum Jubilee service of Thanksgiving on Friday, without speaking at all.

Royal watcher Neil Sean has also said that the pomp and ceremony of the Queen's service of Thanksgiving at St Paul's Cathedral would have been a stark reminder to Prince Harry of what he has given up.

Richard Eden believes that the Princess's blocking move was deliberate, and Ms Elvin added that it seemed orchestrated.

Royal correspondent Victoria Murphy chipped in, saying that she thought the seating was decided in advance.

Meghan Markle and Prince Harry were also greeted by a mix of boos and cheers as they arrived at St Paul's Cathedral, with the couple continuing to smile while walking inside and being greeted by clergymen in attendance.

While the pair were walking down the nave, Sky News commentator Rhiannon Mills briefly addressed the relationship between the Sussexes and the rest of the firm by speaking of an enormous snub.

It is clear that Princess Eugenie and Princess Beatrice's seating arrangement has caused quite a stir and left Prince Harry and Meghan Markle absolutely furious.