My immediate response to the news Prince Harry is planning to rush back from California to be by the bedside of his Pa: at least there is one silver lining to the grim news of the King’s cancer.

Perhaps it would mean that the wounds between father and son – and even between warring brothers – might finally start to heal. After all, fractious families often come together when one of their members faces a terrifying medical diagnosis.

Family unity must surely be the King’s dearest wish – remember his desperate plea to the battling brothers after Prince Philip’s funeral: ‘Please boys don’t make my final years a misery.’

How truly wonderful it would be if the bitterness between Princes William and Harry could dissipate in these most difficult of circumstances. If they united in a common cause of love and concern for their father.

A smiling King Charles and Queen Camilla leaving Clarence House this afternoon 

Prince Harry arriving at Clarence House this afternoon to meet his father King Charles 

Harry and Meghan walk  behind senior royals at a Commonwealth service in London in 2020

Despite the King’s closest aides admitting recently that his relationship with his younger son was now ‘firmly rooted in rock bottom’ – with rapprochement ‘a long way off’ – I dared to hope that Charles’s cancer diagnosis, awful though it is, could at least bring the lost lamb back in to the fold.

But then, reality kicked in and I thought to myself: ‘How exactly would it work?’ How could the family forgive and forget all the wrongs Harry has visited on them?

He has traduced them in the most cruel ways imaginable, accusing them of emotional neglect and even racism (although they subsequently denied that they had). How could he be accepted back when he’s not seen his father or family in the nine months since his fleeting visit for the Coronation?

How would the scheduling of the family visits actually work while Charles is undergoing treatment or recuperating? And what of Camilla? The Queen will, I imagine, be the gatekeeper determining who sees her husband where and when. And yet Harry described her in his book Spare – for which he received a $20million advance – as a ‘dangerous villain’ who leaked harmful stories about him to improve her own reputation; he said she was someone who ‘sacrificed me on her own personal PR altar’. Who would blame her if Harry is the least of her concerns?

As for William, whom Harry accused in Spare of knocking him to the floor in a red mist of rage and described in his book as his ‘arch nemesis’, can there ever be a reconciliation?

Then there is the Princess of Wales, whom the Sussexes’ unofficial biographer and mouthpiece, Omid Scobie, described as ‘cold, a Stepford-like royal wife’. And to whom Harry also seems to have referred obliquely – and cuttingly – in Spare: ‘I think for so many people in the Royal Family, especially obviously men, there can be a temptation or an urge to marry someone who fits the mould as opposed to somebody who perhaps you were destined to be with.’

How could Kate bear to be in the same room as Harry – let alone sit by Charles’s bedside alongside him – especially after both she and the King were named by Scobie in his book Endgame as the ‘racists’ who supposedly ‘raised concerns about the skin colour of baby Archie’.

There must be deep resentment, not only on the part of Camilla, William and Kate, but Anne, Edward and Sophie, too, over Harry’s behaviour, says Amanda Platell

What a knife it would be to her heart if Kate happened to visit her father-in-law – who describes her as ‘my beloved daughter-in-law’ – and bumped into anger-filled Harry.

So, in a way, it must be a huge relief for all the working royals that Harry’s visit is likely to be brief. He plans to be in Canada next week with Meghan ahead of his Invictus Games, an event he can rightly be proud of. Surely it was the wisest decision from Meghan to have stayed at home this time when emotions in the family must be running so high.

There must be deep resentment, not only on the part of Camilla, William and Kate, but Anne, Edward and Sophie, too, over Harry’s behaviour. It is they who have remained steadfastly and loyally by the King’s side. They who will soon be working flat out trying to fill on for the King’s public engagements and keep the Firm afloat.

Oh, how different it would have been if Harry was still here as a working royal, sharing the load. But he is not,

Which is why, although my heart yearns for a rapprochement during Harry’s fleeting return, my head tells me it will never happen.