The Queen at 90: Tony Blair on the week that threatened to topple the monarch

Queen Elizabeth approaches her 90th birthday as one of the most popular monarchs of all time.

But for a week after the death of Diana, Princess of Wales, in a car crash in 1997, it seems that she was horribly out of step with the public mood of mourning.

As the royals holed up in Balmoral, one poll suggested that as many as one in four people was in favour of a republic in a week that saw the whole concept of monarchy wobble.

"I was worried," admitted the former prime minister Tony Blair in a special interview with ITV News looking back to that week.

Mr Blair said that the queen's response offers a masterclass in understanding the monarch's ability to reflect and react to public opinion whilst retaining her dignity.

Elizabeth ultimately toured the piles of tributes left to Diana outside the palace before addressing the public in an unusually emotional speech that restored her place in the British public's esteem.

"She got the balance between showing emotion and retaining the respect and dignity of the monarchy," said Mr Blair, who was prime minister at the time.

"And that is her hallmark.

"She reflected, she thought about it, she adjusted, she moved and she then recovered her poise."

Mr Blair said that the response had been a learning curve for the monarchy, and one that provided a template for the royal family as they weather storms in the future.