The rift between Prince Charles, left, and Prince Edward has deepened due to a request Charles couldn't believe his younger brother had the "audacity" to make.

Britain's Prince Edward reportedly has infuriated Prince Charles by asking the heir to the throne to participate in a television documentary about Charles' love life, including his failed marriage to Princess Diana and his longtime romance with Camilla Parker Bowles.

The Prince of Wales was "taken aback" by his younger brother's proposal and so appalled that he could barely speak, British newspapers reported said. "I cannot believe the audacity of the man," he was quoted as telling friends.

Charles reportedly forbade Edward, the Earl of Wessex, from approaching any of his friends, and Parker Bowles was said to be equally dismissive.

Edward owns a film company, Ardent Productions, which is making a 13-part series on the royal family for the Los Angeles-based E! entertainment network.

According to the London Times, Edward made the request to his brother in a telephone conversation in late 2001 - after Edward had already been rebuffed for trying to film Charles' son Prince William at St. Andrews University in Scotland.

At the time, there was already a Buckingham Palace request to leave the young student alone. St. James's Palace publicly criticized Edward after the attempt.

The relationship between the brothers had been improving after Edward's wife Sophie was rushed to the hospital for an ectopic pregnancy last month. But Edward's latest plans are said to have set them back again.

A friend of Prince Charles told the Times: "We were all taken aback by this request from Prince Edward."

The Earl of Wessex has often clashed with his older brother over his apparent willingness to exploit his royal lineage for commercial gain.

Prince Edward's Ardent Productions is said be as much as .5 million in debt, and is relying on worldwide sales and a 5,000 commission for the television series A-Z on Royalty to improve its economic outlook.

Edward reportedly pitched the series as a "behind-the-scenes" look at the royal family, and was expected to include an episode on Prince Charles, his marriage to the late Princess Diana and relationship with Parker Bowles as a guarantee of good ratings.

Edward hoped to meet these expectations because Charles' relationship with Parker Bowles had been so well-documented. He reportedly wanted to use excerpts from Diana's confessional interview with Martin Bashir on BBC's Panorama, in which the princess alluded to problems in her marriage to Charles.

Charles himself admitted to having committed adultery during a 1994 television interview with Jonathan Dimbleby. But Charles bitterly regrets that TV interview, reported The Times, and his friends have been banned from speaking to cameras since then.

A-Z on Royalty is now being regarded as something of a joke, reported The Guardian. So far, Prince Philip, the Duke of Edinburgh, is the only member of the royal family to agree to appear in the series, due to be broadcast later this year.