The source explained: “The children’s attendance is still up in the air because they will only visit the UK if their mother [Meghan] decides to attend.”

They added: “Harry is hoping that they will join him so that they can all enjoy the service, and everyone can meet up with members of his family while they are over.”

Archie, four, and Lilibet, two, currently reside and are being raised in Montecito, California along with their parents.

The Sussex children have barely set foot in Britain, with Lilibet only travelling to Harry’s home country once in 2022 during the Platinum Jubilee celebrations for the late Queen Elizabeth.

During their last visit, which took place in June, the Montecito family also celebrated Lilibet’s milestone birthday as she turned one and even threw a party at their then-UK residence, Frogmore Cottage.

But experts have continuously raised their concerns over the children being absent from King Charles’s life – something which, according to sources, has left the monarch heartbroken – particularly after his cancer diagnosis.

Royal commentator Michael Cole once labelled the lack of time the King gets to spend with his grandchildren from Montecito as “very sad”.

He told GB News: “Well, the fact is he [King Charles] is not seeing his grandchildren.

“He has hardly seen Prince Archie and I am not sure he has even since Princess Lilibet more than once. It is a very sad state of affairs.”