Harry and Meghan would accept offer to spend Christmas with the royal family at Sandringham...but are yet to receive an invitation from King Charles - as insiders reveal the monarch is determined to 'step up' his grandfather duties

Prince Harry and Meghan Markle would accept an invitation to spend Christmas with King Charles and the rest of the Royal Family at Sandringham, insiders claim, adding that they might require 'heightened protection' to make it happen.  

The Duke of Sussex, who lives in California with Meghan Markle and their two children, Archie, 4, and Lilibet, 2, is understood to have spoken to King Charles on Tuesday in a phone call for his father's 75th birthday. 

Sources told The Times that the conversation could be a 'turning-point' in the difficult relationship between the Sussexes and King Charles.   

This has now been followed by suggestions that the couple would be willing to accept an invitation to spend the festive season in Britain. It was also suggested that they would also be willing to accept an invitation to Balmoral, in Scotland, during the summer.

'I can't imagine the Sussexes would decline an invitation to spend time with His Majesty,' a source that The Times described as a 'friend' told the newspaper. 'As of yet, there have not been any invitations for the holidays.'

The thaw in their relationship comes after a source told the Mail on Sunday that King Charles wanted 'to spend more time with his grandchildren. There's so much love there.' 

It is understood that another phone call between California and Britain is planned for the coming week.

Prince Harry and Meghan Markle last spent Christmas at Sandringham in 2018. 

Sources close to the couple suggested that they would need both 'heightened protection' to be able to realise any invitation.

In March, King Charles requested that Harry and Meghan vacate Frogmore Cottage, their home in Windsor. They fully moved out in July.

Sources close to the couple told The Times that without a residence in Britain, the Sussexes would require a 'formal invitation' from King Charles or Buckingham Palace to be able to stay in a residence that has sufficient protection.

Prince Harry no longer benefits from police protection while he is in the UK, following a decision by the Home Office to withdraw it. The Duke of Sussex has sought to pay for the protection himself.

A legal representative told The Times that Prince Harry was 'unable to return to his home' because it is too dangerous. Aides to the Royal Family said that accommodation for the Prince was likely to be made available for short visits, if any requests are received. 

The revelation that the Susssexes would accept invitations to spend time with King Charles in Britain suggest that they are seeking to repair relations that have been damaged over recent years.

The Sussexes' children, Archie and Lilibet, have spent little time with King Charles. They have never spent Christmas with their grandfather and this distance is said to cause upset for both sides. 

They are understood to have made a video singing Happy Birthday for the King which was shown during the call on Tuesday.

King Charles appears to have telegraphed a desire to be a more involved grandfather, with sources telling the Mail on Sunday that he had stepped up the amount of time that he was spending with the Prince and Princess of Wales' children. 

There had been concerns that King Charles would find it difficult to find time for his grandfatherly duties after acceding to the Crown. Queen Camilla had previously described him as a hands-on grandfather who is happy to 'get down on his knees and crawl about' with his grandchildren 'for hours.' 

King Charles is said to be frustrated at how much personal issues have overshadowed the Royal Family in recent times.

Buckingham Palace declined to comment on what it described as 'private family arrangements' when contacted by MailOnline. 

MailOnline has contacted Archewell, the non-profit founded by the Sussexes, for comment.