THE recordings of Princess Diana made in 1992 by her voice coach Peter Settelen, have long been easy to find on the internet. This evening, the footage will be broadcast in Channel 4 documentary Diana: In Her Own Words.The plan to broadcast the tapes has triggered outrage. Ex-royal butler, Paul Burrell, declared it a “step too far”; Dickie Arbiter, former spokesman for the Queen, pronounced it “shameful”; Diana’s friend Rosa Monckton called it “a breach of privacy”. Her brother, Earl Spencer, begged Channel 4 not to screen them.

The heat around the tapes, however, is nothing new. Twelve of them were found in a police raid in Burrell’s home in 2001, and were returned to Settelen following a lawsuit, after which he sold them to the US network NBC. The BBC even came close to broadcasting them in 2007, then shelved the programme.

So on one level the documentary is no big deal. The stuff is out there in the public domain. The Royal Family and the Spencers may be scrambling to close the stable door, but the horse has so long bolted that it’s already galloped along the motorway and crossed the Atlantic to the United States, where it starred in an NBC documentary.

Some 20 years after Diana’s death, there is little that’s surprising in the tapes. Mostly, it’s just Diana, saying, in different words, what was said in the 1992 Andrew Morton book Diana: Her True Story, and in the 1995 Martin Bashir Panorama interview. But there are fresh details – like the fact she and Charles had sex once every three weeks, or that when she went to the Queen for advice she was offered no help, except the comment that Charles was “hopeless”.

Some lines stand out. We learn that Charles’s “whatever in love is” reply to an early interviewer who asked if the couple were in love “absolutely traumatised” her. She also, with acute self-loathing, recalls how she herself answered “yes”, “like the fat Sloane ranger I was”.

But, for me, probably most shocking is her description of how when she challenged Charles over his relationship with Camilla, he replied: “I refuse to be the only Prince of Wales who never had a mistress.”

It’s not only the Royal Family, but the wider aristocratic class, including her own birth family, the Spencers, that are condemned by her interview. Her parents gave her no hugs, never told her they loved her, sent her to boarding school aged nine.

The message that emerges is about the whole aristocratic mess, the system of power and class that dominates our country. Has that changed? A little, perhaps. Fewer posh people send their children to boarding school at a tender age. Hugs are more in fashion. Hands-on father Prince William was photographed struggling to put baby George into a car seat as he and Kate left hospital following the birth. The stiff upper lip has drooped a little. But there’s still an element that is all about power, hierarchies and keeping up appearances.

What strikes me most is how distant, historically speaking, the plight of Diana now seems. The Royal Family have weathered their bad publicity, shuffled Charles into the background, and are perplexingly more popular than ever. Bolstered by the TV drama The Crown, candid interviews by the princes, and the comparatively plebeian glamour brought by Kate Middleton and Prince Harry’s girlfriend Meghan Markle, they are enjoying a renaissance.

One of the arguments being made to justify tonight’s documentary is that since the two princes made their own documentary, Our Mother, they invited a kind of open season on Diana. Slight as this justification may seem, it does contain the germ of a principle. The Royal Family are good at creating their own propaganda, spinning tales for us, creating images. Since we, the taxpayers, fund this family, there’s a requirement for real stories that crack through the palace’s PR facade.

I don’t feel sullied by having watched the Settelen interviews. It seemed to me that their sleaze factor had been hyped up. In this era of openness, it all seems a little tame and familiar. Watching them, I felt some pleasure in seeing that young woman, relaxed unguarded, feet on the sofa, being more “real” than she had seemed in any other footage I’d seen.

No doubt many people will watch it, not just for scandal, but because there remains an appetite for intimate images and interviews with beautiful women, like Diana, Jackie Kennedy, or Marilyn Monroe, who were caught in the web of power that was the patriarchy of their time.

That said, this footage, old news as it is, isn’t really the documentary we need right now. That film would be one that sheds light on the Royal Family at this moment. Can it really have changed so much since Diana’s time? Isn’t it, surely, just the same patriarchal system and hierarchy, but with a few more modern faces?