PRINCE CHARLES nearly fled in panic from “storybook wedding” to PRINCESS DIANA – book.

“I can’t go through with it,” he wailed, according to a new unauthorized biography.

“Charles: Heart of a King’ by Catherine Mayer says that both the Prince and Diana considered calling off their nups in 1981 because not only did they both know their relationship was flawed but that Diana realized that Charles was still carrying the torch for his former lover Camilla Parker Bowles.

A royal insider told the book’s author that Charles “was desperate” and that Diana was “not the jolly country girl he had assumed” after a brief 5 month courtship. She was reportedly deeply flawed and suffering from an eating disorder.

Diana, the book says, also discovered a bracelet earmarked for Camilla prior to the wedding seen around the world.

“I can’t marry him, I can’t do this, this is absolutely unbelievable,” Diana reputedly confided to her sisters.

But they had told her it was too late to back out because her face was already “on the tea towels”.

Diana and Charles divorced in 1996 nearly 15 years after they first reluctantly tied the royal knot.

Within a year she was dead in a tragic car accident in 1997. Charles finally married Camilla in 2005.