The Duke of York, 64, pulled out of tomorrow’s pre-Christmas lunch at Buckingham Palace, which brings together the whole extended family for a private celebration.

He and his ex-wife Sarah Ferguson had been invited to the annual gathering of over 70 royals, but the Duchess of York is understood to have persuaded Andrew that it was unwise to attend.

The move will come as a relief for King Charles as his younger brother has once again been thrust into the spotlight over a controversial business relationship.

Earlier this week, Andrew and Sarah bowed out of joining the rest of the Firm for the traditional Christmas gathering at Sandringham over the Duke’s relationship with alleged Chinese spy Yang Tengbo.

“It is a tragic downfall for someone who returned from the Falklands War as a war hero,” says royal author Phil Dampier, who is astonished that the King’s brother has pulled out of an event held behind Palace doors.

He said: “I am very surprised that Andrew has pulled out of the Buckingham Palace lunch because it is a private event and he would only be seen arriving in his car.

“Other members of the family are sympathetic towards him, but it seems at the moment he is being influenced by his ex-wife Sarah, who is perhaps playing a longer game now that she is back in the bosom of the Royal Family.”

The royal correspondent of nearly 40 years believes Fergie “is the one controlling it all” as she is keen to avoid any further embarrassment for the King.

Andrew’s withdrawal from Sandringham was also likely to have been influenced by his two daughters’ earlier decision to spend the festivities with their respective in-laws.

But his exclusion from a private family event will likely set a new precedent, bringing his attendance at Easter and even Balmoral over the summer into doubt.

Mr Dampier added: ”If he is now not going to family events like Christmas then what is his future?

“For the foreseeable future, Andrew appears to be a complete outcast.”

Today’s lunch will see the monarch invite the wider family, who will not join the king at the Sandringham estate next week.

However, Andrew’s absence will further isolate the Duke as he and his ex-wife prepare to spend Christmas day together at Royal Lodge in Windsor, the home they still share at the Windsor Estate.

The ongoing stalemate over the 19th Century Grade II-listed property continues to be a bone of contention between the brothers, after the King’s repeated attempts to move Andrew into the smaller Frogmore Cottage.

The monarch is understood to have recently told Andrew he will now have to pay his own costs for the upkeep and security of the 30-room mansion, which will prove difficult for the non-working royal in the long term.

This year will mark the first time since the Duke stepped down from public life after the furore over his friendship with convicted sex offender Jeffrey Epstein that he has not joined his family for Christmas, except during the pandemic.

After his disastrous Newsnight interview in November 2019 – which led to his removal as a working royal – Andrew joined the family at Sandringham but did not join the Royal Family on their traditional walk to St Mary Magdalene church on Christmas morning.

However, he was pictured walking to church with his brother Charles for an earlier private service.

The Christmases of 2020 and 2021 saw the usual pilgrimage to Sandringham cancelled due to the coronavirus pandemic, but when normality resumed in 2022, King Charles invited his brother back into the fold.

Charles’ first Christmas as monarch saw Andrew join the Firm for the public walkabout for the first time since the Epstein scandal forced the Duke to retreat from public life.

And last year, the monarch even invited Sarah Ferguson to attend church with the Firm – the first time she had joined the royals since the early 1990s.

But his association with a Chinese spy appears to have brought an abrupt end to his already limited inclusion in public events.

Earlier this week, it was revealed in a High Court hearing that Mr Yang, who was banned from the UK, was said to have been a “close” confidant of Andrew.

The businessman has insisted it was “entirely untrue” to claim he was involved in espionage and that he has “done nothing wrong or unlawful”.

Mr Yang, previously referred to only as H6 in the legal case, was the founder-partner of the Chinese arm of the duke’s PitchPalace initiative and twice visited Buckingham Palace in 2018 to meet with the late Queen’s second son.

He is also said to have entered St James’s Palace and Windsor Castle at Andrew’s invitation.

On Friday, the duke’s office said Andrew “ceased all contact” with the then-unnamed businessman when concerns were first raised about him.

Andrew met Mr Yang through “official channels” with “nothing of a sensitive nature ever discussed”, a statement said.

Though the Duke stepped down as a working royal in 2019, it wasn’t until three years later that the Queen stripped him of his honorary military roles, remaining royal patronages and he gave up his HRH style in a dramatic fallout from a US civil sex case brought against him by Virginia Giuffre.

Andrew reached an out-of-court settlement with Ms Giuffre a month later, and made no admission of guilt.

The duke no longer attends key events such as Trooping the Colour, Remembrance Sunday or the annual Commonwealth Day service, but he has been able to attend family events such as Christmas, Easter and the King’s Coronation.

In February, he was pictured leading the Royal Family to a memorial service at Windsor Park after Prince William pulled out at the last minute.

But now it seems that Andrew will not be welcome at even family gatherings.