What a terrible error of judgment Prince Harry has made. Just days after landing back in California after a triumphant UK trip during which he met his father for the first time in 19 months, the Prince has once again displayed the least attractive quality he inherited from his mother Princess Diana – her utter paranoia.

At least Diana had good reason, having been cruelly duped by the disgraced BBC journalist Martin Bashir who manipulated her into that infamous 1995 Panorama interview by feeding her lies, telling her that even her most trusted courtiers were traitors who were selling untruths about her to the media.

Now, nearly thirty years after his mother’s death, sources ‘close to Harry’ are making the same lurid accusations Diana made – just days after what should have been a game-changing meeting with his Pa. They say that the Palace’s ‘men in grey suits’ were working against Harry and ‘sabotaging his reconciliation with the King’.

As small glimpses of the meeting between Harry and his father began to emerge in the days afterwards, a source close to the Prince claimed he was infuriated with the briefings, stating rather pompously: ‘The relationship between the Duke and His Majesty The King is a matter for the two of them only’, before adding that ‘the men in grey suits should stay out of it’.

Our Harry never misses a trick to remind us he is a Duke, second son of the King of England. Nor an opportunity for his camp to brief, almost immediately after Harry’s 50-minute cuppa with his father, that it signalled a ‘thawing of their relationship’ and the ‘acceptance’ of his family ‘back into the royal fold’.

The vehement denials that followed surely must have stung Harry as Palace insiders began counter-briefing that Harry ‘would never be allowed to return as a half-in half-out working royal’, that there were ‘no plans now or in the foreseeable future for father and son to appear together in public’ and perhaps most painfully that ‘those inside Team Harry had mistaken a brief tea and a slice of cake for the Treaty of Versailles’.

Others claimed that the meeting between father and son had been ‘distinctly formal’, with the duke allegedly describing it as ‘very official, like an official visit’ – a comment his spokesman vehemently denied.

Now, after the latest lurid accusations that ‘men in grey suits’ are sabotaging the Prince, the harsh reality is clear: the only thing sabotaging Harry is his own self-perceived victimhood, a role he continues unhealthily to wallow in – and unforgivably monetise through his memoir, Spare.

How paranoid must Harry have felt then when it was reported that Buckingham Palace had been left ‘saddened and perplexed’, increasingly ‘bemused’ and ‘clearly not a little irritated’ by Harry’s ‘wild, conspiracy theories’.

Even more upsetting for Harry is that the latest comments have been met with ‘disappointment’ by friends of King Charles, with a royal source adding: ‘The reality is that senior aides have been working behind the scenes to improve what is a delicate but important private family relationship.’

At which point, we should point out that in refined royal circles, the word ‘disappointment’ is equivalent to a nuclear warhead going off.

Harry’s obsession with conspiracy theories has horrible echoes of his mother’s bitter and collapsing marriage to Charles – and her completely out-of-kilter state of mind back then. I can tell you as a former newspaper editor that Diana often called or met up incognito with her favourite journalists to make sure they reported her side of the story.

It was through a tip-off from Diana’s camp that the newspaper I then edited published the first ever pictures of Diana with her then lover, the Muslim heart surgeon Hasnat Khan, after her divorce. Diana let it be known she hoped to marry Khan, even releasing pictures of herself meeting his family in Pakistan. The Princess was a master media manipulator.

So perhaps that’s another thing Harry thinks he has inherited from his mother: an ability to control the media narrative. Although, compared to Diana, he is a clumsy amateur.

But it’s the paranoia that Harry shares with his late mother that is most troubling. For it was not only Diana’s least attractive characteristic, but the one that led to much unhappiness.

After her Panorama interview with Bashir aired in 1995, she and Charles divorced barely one year later. She was ignominiously stripped of her HRH title, devoid of any Royal status and essentially abandoned as a mere private citizen.

To her credit, Diana then gave up playing the victim and forged a new role for herself, championing the removal of land mines in Angola and focusing on her most cherished charities, as well spending time with her beloved boys.

Yet Diana never did stop manipulating the media or blaming the men in grey suits for her unhappiness. She was so paranoid that she cancelled her official Scotland Yard protection detail, believing they were loyal not to her but the palace. And look how that ended.