Lawyers on Monday challenged a coroner's decision to preside without a jury over the inquest into the deaths of Princess Diana and Dodi Fayed, arguing that her decision to act alone gave the appearance of impropriety.

The legal appeal at London's High Court was made by Fayed's father Mohamed al Fayed, lawyers for his Ritz Hotel in Paris, and the family of Henry Paul, who drove the car in which he, the princess and Fayed died in Paris in 1997.

Al Fayed, millionaire owner of Harrods department store, is dissatisfied with Dame Elizabeth Butler-Sloss' decision that she would hear evidence and determine what caused the couple's deaths.

"We believe there should be a jury to aid the coroner and come to a decision," said Michael Cole, al Fayed's spokesman.

The lawyer for the Ritz, Michael Beloff, argued that because Butler-Sloss had been the deputy coroner of the Queen's Household, there would be the perception that she "lacked independence," to assess the allegation that Diana and Fayed had been murdered.

The appearance of independence and impartiality was important "when the death under investigation is the death of a royal princess, mother of a future king, in controversial circumstances, and where royal princes and the royal princess' sister are interested persons," Beloff said.

Beloff also complained that Butler-Sloss had been involved in a police investigation, which concluded the couple's death was a tragic accident.

"She cannot sit. If she can, she should not. If she does, she must not sit without a jury," Beloff said

The decision that she could sit was "wrong in point of law and fatally flawed," he said.

Butler-Sloss, Britain's former top female judge and a member of the House of Lords, made the decision last month to sit alone during the inquest, which is expected to begin in May. Butler-Sloss said in her January decision that a jury could find it difficult to cope with the volume and detail of the evidence.

The inquest — which is likely to have more than 30 witnesses testifying, some by video-link from Paris — will delve into technical matters on the crash, creating a video simulation and expert testimony.

The inquests could begin only after the investigations into the August 1997 deaths of Diana and Fayed was complete. A two-year French investigation, a three-year Metropolitan Police inquiry in Britain and repeated legal action by al Fayed have delayed the inquest by nearly 10 years.

Al Fayed's legal team had pressed the judge to call a jury, saying it was the only way the public would be satisfied that proper care was taken over the issues surrounding the crash.

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