King Charles III and Prince William are closer than ever amid friction with other members of the royal family, sources have claimed.

The King is said to have dispelled any notion of a rivalry with his elder son, who was front and centre at D-Day commemorative events this week as both the monarch and Kate, the Princess of Wales, continue with their respective cancer treatments.

Duties are being spread amongst an increasingly small number of working royals due to health issues, the departure of Harry and Meghan from the UK for the US after and the withdrawal of Prince Andrew from public life amidst scandal.

As a result, William has found his diary full of public engagements, not least in France this week where he joined leaders from across the world including US president Joe Biden to remember the D-Day fallen.

Sources have suggested that Charles might once have disliked allowing his son to be more visible in public – but with cancer treatment and the ever-smaller number of working royals to hand, he has been happy to change his thinking.

A friend of the King says that in recent years, Charles has consulted his son on tricky family issues involving the likes of Prince Andrew and Harry and Meghan. Their joint efforts to tackle these issues is said to have boosted both their personal and working relationship.

‘If there was ever a green-eyed monster or a sense of rivalry between the two, that is a chapter of the past,’ the friend told The Times.

‘The King sees his son as a useful ally on family matters and increasingly in discharging the duties of nation and state.’

A source close to William added: ‘He very much wants to support his father. That isn’t something new, but of course with everything the King is going through with his treatment, he will continue to support him as much as he can.’

Charles was not completely absent from this week’s commemorative events in Normandy. He and the Queen attended a memorial ceremony on Friday at Ver-sur-Mer alongside French president Emmanuel Macron and his wife Brigitte.

But William was front and centre as colonel in chief of the Army Air Corps – whose tie he wore. Ironically, the AAC trained Prince Harry as an Apache helicopter pilot.

The younger son of the King was not, however, present in France for the memorial services, despite his widespread and heavily publicised support for military veterans through the Invictus Games and associated charitable enterprises.

Observers have suggested there is still a rift between Harry and his father as well as the rest of the royal family following his decision to quit frontline royal duties.

Frictions were only exacerbated with a number of TV interviews featuring slights towards the family, and Harry’s autobiography Spare, which contained details about his fraught relationship with his older brother.

Harry did not see his father when last in London in May for an Invictus Games ceremony, despite being a stone’s throw from Buckingham Palace, where a garden party was being held at around the same time.

He did, however, see the King briefly in February shortly after the monarch’s cancer diagnosis was made public.

William, meanwhile, was seen speaking with D-Day veterans on June 6 – telling one hero Kate ‘would have loved’ to have attended the 80th anniversary ceremonies.

The Prince of Wales is also believed to have been a valuable source of counsel for the King as Charles has sought to address the other elephant in the room – his younger brother Prince Andrew.

Charles is currently at loggerheads with Andrew over his residency at the Royal Lodge. The Duke of York has been living in the £30million household largely removed from public life following the Jeffrey Epstein scandal.

He is thought to be resistant to the idea of moving out into the smaller Frogmore Cottage once called home by Harry and Meghan.

But Charles is thought to have threatened to sever ties with Andrew altogether unless he acquiesces – with William believed to be lined up to move in in his place.

Such a falling out would see Andrew charged with paying for his own security, accomodation and lifestyle without a royal allowance. Recent images have suggested the Royal Lodge has fallen into a state of disrepair under the Duke.

With William there to serve as a sounding board, and with his cancer treatment continuing, it is of little surprise that the Prince of Wales is playing a larger part in senior royal duties on behalf of and alongside his father.

He will ride behind his father’s carriage in a modified review of the troops during Trooping the Colour; later this month he will also join his father at the garter service at St George’s Chapel in Windsor, and at Royal Ascot for a day at the races.

He will also attend the upcoming state banquet thrown for the emperor and empress of Japan on June 25 – giving him, as his father had before him, further training in the world’s most high profile apprenticership.