Prince Harry’s potential attendance at Prince William’s 48th birthday party could create tension between him and Meghan Markle, according to a royal expert.

The Duke of Cambridge celebrated his birthday on June 21, just a few weeks after Harry and Meghan returned to the US following a visit to the UK for the Queen's Jubilee celebrations.

As birthday parties are typically a time for gathering family and friends, it has been reported that Kate is very keen to invite Harry back for a party to mark her husband's birthday.

However, royal commentator Neil Sean has claimed that the Duke of Sussex's potential attendance at the party could create a storm.

“That big party, which we believe will be held at Windsor Castle, could create a few problems,” he told viewers of his YouTube channel.

“It does appear that there's a bit of shall we say friction between Prince Harry and Meghan Markle according to a very good source, and as ever we have to say allegedly.”

Neil suggested that Harry would be keen to return for the celebration, despite rumours of a royal rift between the pair following Harry's controversial interview with Oprah Winfrey.

However, with two young children to take care of in California, Meghan might not be so keen to head abroad so soon after the Jubilee trip.

“But according to that good source, Meghan Markle is not keen at all to go back into a room, some might say a hornet's nest of which she did her own stirring, to spend an evening, afternoon, day, whatever that might be celebrating someone who clearly has got issues with her and likewise vice versa,” he continued.

Neil acknowledged that formal invitations have yet to be issued, but suggested that if both the Duke and Duchess of Sussex are invited, Harry could be forced to decide whether to attend alone.

Recently, Prince William has been urged to act like a future king and extend an olive branch to his estranged brother.

Royal author Duncan Larcombe, while talking to Daily Beast, urged Prince William, who is second in line to the British throne, to start acting like the king and mend the alleged rift with the Duke of Sussex.

“If William wants to be a future king, a great leader giving inspiring addresses about the environment to two billion people, then the public are within their rights to expect him to be able to sort out a frankly pretty minor dispute with his brother,” said Duncan.

He went on to say that the Duke of Cambridge should show some leadership and eventually pick up the phone to call Harry from across the pond.

Meanwhile, according to a report by International Business Times, it is believed Prince William refuses to reconcile with Harry because the future king is not at fault.

“William is very protective of his wife and children and won't expose them to any unnecessary hurt or drama,” a source told the publication.

It is worth noting that Harry and Meghan have been making headlines recently due to their explosive interview with Oprah Winfrey, where they spoke about their time in the royal family and the reasons for their departure.

The couple made several shocking claims, including accusations of racism and a lack of support from the royal family.