The King was almost absent from Balmoral in the hours before his mother died because the seriousness of her condition was unclear, a new book has revealed.

He was only persuaded by courtiers to be ready to make the journey to Elizabeth II’s bedside in the hours before she died on Sept 8 2022.

An account of her final moments, and her son’s succession to the throne, has been published for the first time in a new biography of the King.

It reveals how the monarch, who at the time was the Prince of Wales, was advised by royal staff that he needed to make a decision as to whether to fly to Balmoral, despite there being no public sign that the Queen’s condition was about to worsen dramatically.

The Prince was at the opposite end of Scotland holding a series of charitable engagements at Dumfries House in Ayrshire, where he had been receiving regular updates.

The book records how he was faced with the dilemma of pressing on with business as usual or dropping everything and heading to Balmoral the next morning.

The Prince was mindful that travelling to Balmoral would set off alarms across the Government and the media, signalling the Queen’s imminent demise. He was also aware that there had been similar lapses in the Queen’s health before and that there had been a sudden downturn at the end of 2021.

But by the evening of Sept 7, both the Princess Royal and Sir Clive Alderton, the Prince’s private ­secretary, were advising him to be on standby.

The book by Robert Hardman records one member of staff recalling: “They were both saying to him: ‘Think how you would feel if you never said goodbye. [Sir] Clive said that if it did turn out to be the wrong call, then they could blame it on him.’”

The following morning, the Princess Royal called again and told the Prince to come at once, the book records.

A helicopter, which was already on standby at Dumfries House waiting to take the Duchess of Cornwall to engagements in other parts of Scotland, was issued with a new emergency flight plan.

Shortly before 9.30am, the royal couple climbed aboard with a small team including Sir Clive, the Duchess’s deputy ­private secretary and a protection officer.

During the one-hour flight, the Prince began re-reading his briefing papers on the initial phases of Operation London Bridge, the plan for the immediate aftermath of the Queen’s death.

Hardman writes that Sir Clive later told staff that he was hoping this would be an unnecessary trip and was half-expecting the Prince to arrive at Balmoral only to be greeted by the Queen on the doorstep, arms crossed, asking: “What on Earth do you think you are doing?”

However, when the Prince and the Duchess of Cornwall touched down at Balmoral it was clear this was not a false alarm. Although the Queen was stable, she was slipping away.

The book records how following what would turn out to be a final visit to his mother’s bedside, the Prince went on a foraging trip for mushrooms to “clear his head”.

During his return to Balmoral he pulled over to take a phone call in which he was addressed for the first time as “Your Majesty”, indicating that the Queen had died and he had succeeded to the throne.