The butler’s ears were ringing with the words: “Yes, I am asking you to lie! I am the Prince of Wales and will be king. So Yes! YES!”

Burrell’s crime had been to inadvertently give Princess Diana a clue to Charles’s little secret.

Instead of getting an early night, the Prince had sneaked out from Highgrove to visit his mistress Camilla Parker Bowles, who lived 11 miles away.

But this time Diana had unexpectedly phoned Highgrove and Burrell had answered. “I don’t suppose the hubby’s around is he?” she asked.

Burrell’s mind raced as he tried to think of a diplomatic response, settling for: “I don’t know, your Royal Highness.”

“Of course you do Paul,” replied Diana. “You know everything that happens down there. Now, where has he gone?”

The unfortunate butler found himself trapped between duty and loyalty.

He pleaded with her not to press him, adding: “The best person to ask would be His Royal Highness, not me.”

Diana also squeezed out of him details of who else had phoned that evening, giving her the ammunition to make out she knew all the goings-on.

“That night I went to bed worried sick,” recalled Burrell. The next day valet Michael Fawcett told him: “He wants to see you and he isn’t happy.”

Charles was standing near his table and told the butler to shut the door.

“He was indignant. ‘Can you tell me why – why – Her Royal Highness is constantly aware of who visits or phones Highgrove when she isn’t here?'”

Asked when he had last spoken to Diana, Burrell replied the previous evening “when you were out”.

“His face was puce red. ‘WHY?’ he bellowed. ‘Because you were out, Your Royal Highness’.

“Puce turned to virtual purple. ‘Why couldn’t you simply have said that you just couldn’t find me?'”

Shaken, Burrell asked whether the Prince was telling him to lie.

“With the temerity of that question from a servant, he expl0ded: ‘Yes! YES! I am!’

“In a flash, he picked up a book from his table and hurled it in my direction.

“I can still see the fluttering pages whirring through the air. It missed but I don’t think it was intended to hit me.”

Burrell said Charles was still ranting and stamping his foot and stormed: “I am the Prince of Wales and will be king!” The butler made a sharp exit.

As early as August 1988, the Prince told Burrell not to write the names of his lunch guests – including Mrs. Parker Bowles – in the pantry diary as Diana had started looking there.

Charles’s trysts with Camilla had been slowly coming to the attention of staff at Highgrove.

He would tell Burrell: “I’ll have dinner early and then retire.” Burrell said the lounge would be laid out to give the impression the Prince was having a quiet night in, with The Times open at the TV page and logs piled by the fire.

But, of course, it was not just Charles who was leading a secret double life.

Burrell remembers the first time Diana entrusted him with a “mission” – to smuggle James Hewitt into Highgrove. It was the first of many.

He said: “The Princess got straight to the point. ‘I would like you to run an errand for me. I don’t want anyone, and I mean anyone, else to know about it’.

“‘Will you go to Kemble station tomorrow and pick up someone? You will be picking up my special friend Major James Hewitt’.

“The Princess was waiting for us. She embraced her ‘special friend’. She was glowing.”

Burrell stresses that Hewitt only became a visitor to Highgrove “long after” Charles had begun cheating on Diana.

The butler was spurred on by seeing the crushing effect the Prince could have on his wife.

Once, during a visit to Japan, Diana came down the stairs in a Catherine Walker red tartan coat dress. Charles told her she looked like “a British Caledonian air stewardess”.

The couple’s strained relationship was coming to a head around late 1989 and 1990.

Burrell recalls walking into the sitting room and finding Charles, in his dressing gown, on his hands and knees picking up cutlery from the floor.

Glasses were overturned and broken on the table and salt was scattered over the table.

“Oh dear,” he said. “I must have caught my dressing gown on the table.” The Princess was nowhere to be seen.

Source: DAILYMAIL CO UK