Channel 4 has denied that a documentary about the car crash which killed Princess Diana contains graphic images of the victims.
The Conservatives say the film would hurt the princess's family
Following a newspaper report, shadow culture secretary Hugo Swire urged the channel's bosses to cancel the show, Diana: The Witnesses In The Tunnel.
Due to be shown on 6 June, it includes pictures taken by French photographers following the 1997 collision in Paris.
Channel 4 said none of the images identified Diana or the other victims.
Diana, 36, Dodi Al Fayed, 42, and driver Henri Paul were killed when their Mercedes crashed in the Pont de l'Alma tunnel in Paris as they drove away from pursuing paparazzi after leaving the Ritz Hotel.
The Observer reported the Channel 4 film features a picture of the Princess of Wales being treated with oxygen by a French doctor, along with images of the inside of the car.
Interviews with photographers who were at the scene and other witnesses are also included, the paper said.
But Channel 4 said the Observer article was "both misleading and inaccurate" because much of it is was based on the views of people who had not seen the film.
"The death of Diana, Princess of Wales, has been a defining moment in British contemporary history, affecting the public's view of the monarchy and of celebrity photographers.
"We acknowledge that there is great public sensitivity surrounding pictures of the victims and these have not been included.
"Only one image shows the occupants of the car after the crash and it has been appropriately obscured to avoid any unwarranted intrusion into their privacy or that of their families.
"We are confident that once people have seen this film they will agree that it is a well-made and responsible documentary."
Reacting to the newspaper article, Mr Swire said the coverage would be "deeply distressing" to Princes William and Harry.
Diana's friend Rosa Monckton told BBC Radio Four's The World at One the decision to broadcast the pictures was designed to boost ratings.
"It's rather like...how people stop on a motorway to look at car crashes. But they are summoning people; they are saying 'roll up, roll up - come and look at this'.
"She can't be hurt by it but her boys can. Above all else, Diana was a mother," she said.
The press director for Mohamed Al Fayed, Katharine Witty, told the BBC it was nonsense for Channel 4 to argue it was acting in the public interest:
"It is a sleazy attempt to gain ratings so I think there would have to be a lot of pressure on them for them to pull it. "
But I hope they have the decency at least to hand over the new material they have to the coroner so that it can be judged fairly by the jury."
Channel 4's head of history, science and religion, Hamish Mykura, said suggestions they had been "masterminding" a publicity stunt were untrue.
He added the photograph showing the interior of the car with its occupants blanked out had been published in the Sun newspaper last July.
A three-year inquiry conducted by former Metropolitan Police chief Lord Stevens concluded Princess Diana had died in a tragic accident. Chauffeur Henri Paul was speeding and over the legal drink-drive limit, it said.
In 2004 Princess Diana's brother, Lord Spencer, said he was "shocked and sickened" by the broadcast of photographs of his dying sister by US network CBS in a programme on the accident.
Inquests into the deaths of Princess Diana and Dodi Al Fayed are due to begin in October.