THE rule of Charles III may weaken Scots' commitment to the Union, according to the royal biographer Clive Irving.

"The Queen held everything ­together," he said. "Having been on the throne for so long, she ­represented a degree and continuity that can't be replicated."

The author of The Last Queen also predicted the SNP's current ­commitment to the monarchy will "expire" with the Queen's death, ­according to Time Magazine.

Recent polls have found that only 52% of Scots think Charles will be a good king, compared with 75% who thought the Queen performed her role well.