When Princess Diana was beset with worries in 1995 that she would be killed in a staged car accident, she voiced her fears to the man she trusted most, her lawyer Lord Mishcon.

His firm, Mishcon de Reya, handled her highly acrimonious divorce from Prince Charles, which was finalised the following year.

After the Princess died in a car crash in Paris in 1997 alongside Dodi Fayed and driver Henri Paul, Lord Mishcon passed his contemporaneously typed-up account of his meeting with Diana to senior Metropolitan Police officers who put it in a safe. But the note was not passed to French authorities investigating her crash for six years.

The Princess’s brother and sisters did not learn of its existence for more than a decade after it was written. Princes William and Harry were also left in the dark for a long time.

At his meeting with police chiefs the month after Diana’s death, Lord Mishcon (who died in 2006) read his note aloud to stress its importance. He told officers that it recorded Diana saying ‘efforts would be made if not to get rid of her by some accident in her car, such as a pre-prepared brake failure, at least to see that she was so injured or damaged as to be declared unbalanced [in her mind]’.

I can disclose that, in a remarkable turn of events, Prince William has now turned to Diana’s lawyers again.

Prince William has instructed law firm Mishcon de Reya to act for him and his family

The late Lord Mishcon’s firm represented Princess Diana in her acrimonious divorce from Charles

The heir to the throne has instructed Mishcon de Reya to act for him and his family, in a break with tradition.

William has previously been represented by King Charles’s lawyers, Harbottle & Lewis, in particular its partner, Gerrard Tyrrell.

‘William wanted to strike out on his own,’ a source tells me. ‘He did not want to continue using his father’s lawyers. It’s as simple as that. He wants to be his own man.’

A Kensington Palace spokesman declined to comment, but the instruction is the talk of legal circles. It is said to have disappointed Harbottle & Lewis, which has represented the Royal Family for decades. Media law specialist Tyrrell is one of the King’s most trusted advisers.

Harbottle & Lewis acted on behalf of the Royal Family in 2006 in the News of the World royal phone-hacking scandal, which led to the closure of that newspaper. Its reporters had hacked into the mobile phones of both Princes William and Harry.

But William’s move will have delighted Mishcon and its deputy chairman Anthony Julius, who was chosen by Diana as her legal representative when she divorced Charles.

Julius continued to work with William as one of the founding trustees of the Diana, Princess of Wales Memorial Fund and was vice-president until it closed in 2012.

William’s decision is being seen at Buckingham Palace as the latest example of his desire to follow a different path from that of his father.

The peer, who died in 2006, passed his contemporaneously typed-up account of a meeting with Diana to Metropolitan Police officers after the Princess’s fatal car crash in Paris in 1997

Of course, his inheritance of the vast Duchy of Cornwall estate when Charles ascended the throne in 2022 means that money is no object.

Valued at more than £1billion, the estate includes more than 200 square miles of land in over 23 counties and provides William with an annual income of at least £20million.

‘William wants to do things differently from his father, and wants to be seen to do them differently,’ a friend tells me.

This was made clear in 2023 when William chose to give a major interview to a national newspaper that was published the day after Trooping the Colour. It meant that coverage of the King’s first birthday parade was overshadowed by his heir’s declaration that he planned to end homelessness.

William’s decision to branch out from his father’s legal advisers shows that he is more than willing to shake up the status quo behind palace doors as well.