Any jury at the inquest into the death of Princess Diana will be drawn from the public, the coroner has said.
The coroner has said a joint inquest would be less upsetting
Lady Butler-Sloss told a preliminary High Court hearing that she wanted the inquest in May and did not want the panel drawn from the Royal Household.
She reserved her decision on whether there would be a jury or joint inquest.
A Metropolitan Police investigation last month concluded the 1997 Paris car crash in which Diana and Dodi Al Fayed died was a tragic accident.
Lady Butler-Sloss said she would hold a joint inquest if shown to have jurisdiction on the matter.
She suggested it would be "unbelievably expensive" to hold separate inquests into the deaths.
The court was told at least 40 witnesses are likely to be called. There would be a need for interpreters and video-conferencing facilities.
Lady Butler-Sloss, who held the hearing in public after initially deciding it would be held in private, said separate inquests would also be upsetting for the families.
Jamie Lowther-Pinkerton, private secretary to Princes William and Harry, said they hoped the inquest would "move swiftly to a conclusion".
Reserving her decision, Lady Butler-Sloss said: "I'd hope to give you my considered written answers by very early next week at the latest."
"Because I am anxious to get going with this I would like to hold the next part of this at the beginning of March."
As the proceedings got under way, Lady Butler-Sloss offered her "deepest sympathy" to the relatives and friends of the princess, 36, and Mr Al Fayed, 42.
The Princess of Wales's sister, Lady Sarah McCorquodale, and Mr Al Fayed's father Mohamed - who is being represented by Michael Mansfield QC - were in court.
Princess Diana and Mr Al Fayed died when their car crashed in 1997
Lawyers for driver Henri Paul, who also died, and sole survivor, bodyguard Trevor Rees, were also present.
In a written submission, the Queen's lawyer, Sir John Nutting QC, said a public jury would avoid an "appearance of bias".
Lady Butler-Sloss said she would be "extremely surprised" if Princes William and Harry would have to give evidence.
She said she expected to make arrangements for hearing the inquests as soon as she received a police report on extensive investigations into the crash in both the UK and France.
The princess, 36, and Mr Al Fayed, 42, died when their Mercedes crashed in the Pont de l'Alma tunnel on 31 August 1997.
They were pursued by paparazzi photographers after leaving the Ritz Hotel for Mr Al Fayed's apartment.
A three-year inquiry, led by former Metropolitan Police chief Lord Stevens, found no evidence of a conspiracy to murder the couple.
Mr Mansfield criticised the timing of the report, saying it had given the impression that the Diana case was now closed.
Mohamed Al Fayed wants a jury to hear the inquest
Edmund Lawson, for the Met, responded: "The Commissioner stands by the decision to publish the report. It was not a decision taken lightly."
Richard Keen QC, counsel for the parents of Mr Paul, suggested Lady Butler-Sloss may be associated with the conclusions of the report.
However, Lady Butler-Sloss, who had agreed to the publication of the report, said: "I don't know whether its conclusions are right or not. I haven't heard the inquest."
Mr Keen said he did not propose that she should stand down, but that the case should be heard by a jury of ordinary members of the public to avoid any suggestion of bias.
Ian Croxford QC, representing the Ritz Hotel, also called for a jury to be brought in.
The inquiry report said Mr Paul was speeding and over the legal drink-drive limit.
The police investigation was requested by royal coroner Michael Burgess when the inquests were opened and adjourned in January 2004.
Mohamed Al Fayed said Lord Stevens' "highly unsatisfactory" report left questions "unanswered".
He mounted a legal challenge for the preliminary hearing into the inquest to be held in public.