In this June 20, 1990, file photo, Britain's Princess Diana and Prince Charles take shelter under an umbrella while attending the second day of the Royal Ascot horse race meet near London. (Martin Hayhow/AP)

LONDON — A British broadcaster will air a somewhat salacious TV documentary about the late Princess Diana on Sunday despite pleas from her family, friends and former courtiers to scuttle a program that includes clips of Diana discussing her sex life and unhappy marriage with Prince Charles.

The British broadcaster Channel 4 defended the use of the private musings of Diana as an important historical document and said the recordings offered unique insights into her life as the anniversary of her death approaches later this month.

Historical as the tapes may or may not be, the Daily Mail tabloid went with the headline: “Charles and Diana ‘didn't have sex for seven years’: How Prince transformed from being ‘all over his wife like a bad rash’ before their love life ‘fizzled out entirely’ after Harry was born.”

Critics called the airing of the clips intrusive.

Dickie Arbiter, author of “On Duty With the Queen,” a book about his years as press secretary at Buckingham Palace, said airing the recordings was “exploitive.” 

“We don’t need to know all these things. He was all over me like a rash? Keep private things private,” Arbiter told The Washington Post.

Regardless, Arbiter predicted that the show would prove irresistible for many who want to watch Diana face the camera and offer some of her most intimate observations.

One of Diana’s former bodyguards, who appears on the program, said the princess would support the airing of the 25-year-old tapes.

“She would love it,” Ken Wharfe told the Associated Press

“’For the first time, she would say, ‘People are actually listening to and hearing what I am saying.’” said Wharfe, who served as Diana’s protection officer between 1986 and 1993.

The documentary, “Diana: In Her Own Words,” is timed to the 20th anniversary of her death in a car crash in Paris on August 31, 1997.

The video clips were taped in 1992 and 1993 during sessions at Kensington Palace with a voice coach named Peter Settelen, who was working with the princess as she prepared to play a more public role, soon after she and Charles separated.

While excerpts of the recordings were previously broadcast in the United States as part of an NBC documentary in 2004, Britain’s Channel 4 said it is serving up never-before-seen footage.

According to the Guardian newspaper, Diana’s brother Earl Spencer pleaded with Channel 4 to shelve the program, reportedly fearing the broadcast could hurt Diana’s sons, Prince William and Prince Harry.

“This doesn’t belong in the public domain,” Rosa Monckton, a longtime confidante of Diana, told the Guardian.

Monckton told the newspaper she believed that Diana treated the taped sessions with her voice coach as informal therapy sessions.

The princes and the palace have declined to comment.

According to news accounts in Britain and promotional materials by Channel 4, the program includes a few new morsels about the private life of Diana. 

On the tapes, the princess recalls that Charles was an ardent suitor. “He was all over me and I thought, you know, ‘ehh.’ Whereupon he leapt upon me and started kissing me and everything, and I thought, ‘What! This is not what people do.’ ”

She said, “He wasn’t consistent with his courting abilities.” 

Diana reveals that the couple spent time together on only 13 occasions before they were wed and that as a newly married couple, they had sex only “once every three weeks and then it fizzled out.” 

She also confesses she believes her bulimia was brought on by a bad match and the stress of isolation.

A statement from Channel 4 reads: “We carefully considered all the material used in the documentary and, though the recordings were made in private, the subjects covered are a matter of public record and provide a unique insight into the preparations Diana undertook to gain a public voice and tell her own personal story. … This unique portrait of Diana gives her a voice and places it front and centre at a time when the nation will be reflecting on her life and death.”