Prince Harry is expected to call King Charles III as he turns 75 today.
But the Duke of Sussex and his family will not travel to London where his father is holding a small celebratory gathering at Clarence House this evening.
The King's 75th birthday will be a working day for the monarch marked by gun salutes across the capital. Charles will launch the Coronation Food Project with the Queen, which aims to bridge the gap between food waste and food need.
Last week Harry re-ignited his public war of words with the Royal Family, declaring that he has had ‘no contact’ with Buckingham Palace over the King’s 75th birthday celebrations.
But it appears there will be an olive branch from Montecito, with a phone call this afternoon or evening due to the time difference in California.
Prince Harry, Duke of Sussex, will call his father on his 75th birthday today, but will stay away from the celebrations
Charles is working today, and will launch the Coronation Food Project with the Queen which aims to bridge the gap between food waste and food need. Yesterday he was presented with a cake at Highgrove
A 'well placed' source told the BBC that Harry would want to speak to his father on his big day.
The King is expected to celebrate his milestone birthday privately with family and friends tonight.
At noon, the King's Troop Royal Horse Artillery, named by Charles's grandfather King George VI, will fire a 41-gun salute from London's Green Park. An hour later, the Honourable Artillery Company will fire a 62-gun salute at Tower Wharf, Tower of London - an extra 21 for the City of London.
Harry's spokesman denied reports that Harry snubbed an invitation to a Clarence House family gathering tonight, saying: ‘There has been no contact regarding an invitation to His Majesty’s upcoming birthday.’
But Buckingham Palace refused to discuss the King’s plans.
A ‘source close to the Sussexes’ told the Mail the couple were not aware the King was holding a celebration until The Sunday Times made the claim.
The paper reported that the King invited Harry but that the Duke of Sussex ‘is not making the trip from California’. It also said he had ‘turned down the offer to spend some time with his father at Balmoral’ over the summer.
A ‘friend’ of the Sussexes even suggested the story was leaked to divert attention from the King and Queen’s visit to Kenya last week, where His Majesty faced calls to apologise for Britain’s colonial past.
They told the Mail: ‘The story is being positioned in a way to make it look like the Duke is snubbing his father, which he is not. Considering the trip (to Kenya) didn’t go well, this might be a welcome distraction.’ It came despite the trip being considered a diplomatic success for both Britain and Kenya.
Prince Harry, Meghan Markle with King Charles and Queen Camilla at the late Queen's funeral last year. Harry has reportedly not spoken to his father for a long time
Prince Harry and Meghan Markle were not spoken to about the party by Buckingham Palace, their spokesman said
Palace circles remained tight-lipped about the Sussexes to calm tensions. Communication between the King and his youngest son is said to be negligible, and between Harry and brother William, non-existent.
Charles and Camilla will today visit a surplus food distribution centre outside London and meet staff and volunteers to hear about the ways in which food waste can be used for social good.
Charles will also host a Buckingham Palace reception highlighting the work of nurses and midwives over the decades as part of the NHS 75 celebrations.
Among the guests will be around 400 nurses and midwives alongside the Chief Nursing Officer of England, Dame Ruth May, and Amanda Pritchard, chief executive of NHS England.
Birthday celebrations began early for the King when on Monday he was guest of honour at a party staged in the grounds of his Highgrove home in Gloucestershire.
Charles joined a host of people, from community stalwarts nominated by friends and family who were also turning 75 this year, to representatives from organisations marking the same milestone, such as the NHS and members of the Windrush generation.
Among the famous faces at the event were celebrity chef Raymond Blanc, The Repair Shop host Jay Blades and singer Lee John from the 1980s group Imagination.
Charles Philip Arthur George was born on November 14 1948 at Buckingham Palace.
After his birth - the first at the royal residence since 1886 - his father the late Duke of Edinburgh drove to Caxton Hall to register the event.