Di ‘would have healed William and Harry rift’

Flowers, photographs and commemorative cakes were displayed near the south face of the palace, where Diana lived until her death in 1997.

Welsh flags and bunting – a tribute to the former Princess of Wales – were brought by Anne Daley, a well-wisher who woke at midnight to catch the early train from Cardiff.

Ms Daley claimed to have been one of the first people outside the palace when news of Diana’s death broke, having lived just a mile away at Rutland Gate.

“It was extraordinary, it was eerie – people couldn’t believe it was just an ordinary car crash,” she recalled.

“The Princess of Wales, dead? Everybody was in shock. People were crying and people were wailing.”

Diana was 36 when she died in a Paris hospital after her Mercedes crashed into a pillar in the Pont de l’Alma tunnel.

The accident also killed her partner, Dodi Fayed, and the car’s driver, Henri Paul.

The princess’s death provoked an outpouring of public mourning that saw the area outside Kensington Palace flooded with flowers.

The roses and Union Flags displayed on the same spot 25 years later, although far more modest, were enough to prompt tourists to stop and take pictures.

Ms Daley suggested that Diana would have bridged the divisions between William and Harry, who recently announced they would mark their mother’s death separately.

“It’s a terribly sad situation because we used to see her quite frequently with the children,” she said.

“I think like most mothers they’d call a family meeting, say, you know: ‘Cut it out, and behave yourselves … stop all this silly nonsense.’”

Her sentiments were echoed by another mourner, Chris Imafidon, who used an umbrella emblazoned with Diana’s face to keep the sun out of his eyes.

“If she was alive, the boys wouldn’t be quarrelling,” he said.

“She knows how to … bring them to her arms and hug them, and say: ‘Come on, come on, you’re brothers, you’re there for each other.’”

Other members of the small crowd said they intended to stay all day to mark Diana’s death, having brought candles for a late-night vigil.

John Loughrey, a veteran royal-watcher, had brought a large cake featuring a picture of Diana originally taken while she was on her tour of Australia in 1983.

Mr Loughrey – who had wrapped a Union Flag bearing Diana’s face around his waist – explained the cake had cost “about” £230.

In the afternoon, he began handing out portions of cake to the crowd, slicing carefully under the icing to avoid defacing the image of Diana.