A prenup for William and Kate? I think not.

Wouldn’t the late Princess Diana be incredibly proud of her son, Prince William, who has behaved impeccably in every way to date? This week he gave a great performance on TV when he and his new fiancée were interviewed for the very first time since news of their engagement broke. Prince William has never put a foot wrong throughout this lengthy courtship. Even when the couple split for a while when the pressure got to them, he behaved as discreetly and protectively of Kate and her family as he always has.

He resembles his mother physically and he has her gift for connecting with people. He is a credit to his family. For me it was seeing Diana’s ring again – given as the greatest token of his love that I suspect Prince William could have given his future bride – that set me off thinking of Diana and the enormous love she had for her boys. That ring, I am certain, has created a deep well of emotion in all those people who are diehard Diana fans. Not forgetting those who simply felt sad for a motherless boy who, despite everything he has, has no mum to be there at such a wonderful time in his life. So he involved her in the best way he could: through her engagement ring, which he gave to Kate.

The story of how he carried Diana’s sapphire and diamond ring in his rucksack in Kenya for three weeks until he popped the question made me laugh. Yes, that’s just the thing a boy would do! (Even though I bet there were one or two bodyguards around to make absolutely certain it never got lost.)

In law, an engagement ring is treated as a gift to the future bride and she is entitled to keep it, unless it is made clear beforehand that it never becomes her property absolutely. Although I suspect that the latter has happened here, I have no worries for this couple. Vultures in the press are already circling, with some commentators suggesting that because of the failure of his parents’ marriage, or because it was his mother’s ring, the ring shouldn’t have been given at all. Nonsense. He loves its symbolism. Kate clearly loves it. Why wouldn’t she love it?

Others, recalling that Charles and Diana divorced acrimoniously, have urged Prince William and Kate to sign a prenuptial agreement, to avoid future marital rancour. Again, nonsense.

Apart from the distasteful nature of such waffle, in my view the existence of a prenup would likely exacerbate any future difficulties. The Prince of Wales clearly provided handsomely for the late Princess of Wales, whose needs were generously met without a prenup. There is no reason to suppose that this wouldn’t be the case for Kate in the future. She couldn’t expect anything more and I doubt Prince William would expect anything less.

I hope that unkind speculation does not put our future Queen under additional and unnecessary stress. As it is, she faces the prospect of an imminent state wedding knowing billions of people from all over the world will be watching her. As Mr Justice Mostyn put it recently in a speech to Parliament – and at that time he had no idea of what was coming – divorce lawyers should definitely not be present at a wedding.

Most lawyers will never put their own money on a racing certainty. But in this case, I am prepared to do so.

I do not doubt that this marriage will work. I think Kate’s parents’ solid marriage and their discreet but solid support for their daughter will help. I hope she always stays as close to them as she is now and doesn’t allow her altered status to affect her family relations. I doubt it, because those parents don’t strike me as the type to give up on her either. They appear to be the souls of discretion.

I watched the television interview in amazement as Kate revealed that, after Prince William had asked her father’s permission to marry his daughter, she didn’t know if her father had told her mother. How could she truly think he hadn’t told his wife such incredible news? The future King of England had proposed, their daughter had become a future Queen-in-waiting… and he hadn’t told her mother?

I tried to imagine myself in that scenario or in fact any scenario affecting my son, and not being told… I found it difficult. Then I suddenly understood that all that discretion, which exists even between family members, helps them to protect Kate in a world that is far removed from the everyday. It may also explain why Kate has never had a “proper” job. She couldn’t afford to risk ending up on the wrong side of any scandalous newspaper story.

So with parents like these, and a husband who is more like “one of us” than any other senior member of the Royal Family, I’d put the odds on a successful marriage at 100%. And if the delicate issue of a prenup is raised by a well-meaning but cautious courtiers, my advice to William and Kate is: bin it – and them – as fast as possible!