She looked at me intently with her massive blue eyes.
‘No,’ she replied firmly, ‘I have no regrets. I wanted to do it, to put my side over. There has been so much rubbish said and written that it was time people knew the truth. But I won’t do it again. Once is enough. I have done what I set out to do.’
I looked over at her son Prince William, just 13 at the time and the only other lunch guest apart from a palace PR lady, and he was staring unhappily down at his plate.
‘Did you think it was a good idea, William?’ I asked him.
He pursed his lips, and his cheeks reddened, then he laughed in a slightly embarrassed way and replied: ‘I’d rather not say…’
If he disapproved of his mother’s decision to spill her guts out about her private life on national TV, he certainly wasn’t going to tell me, then editor of the tabloid Daily Mirror.
But his tense body language told me all I needed to know. (Diana’s friend Simone Simmons told Vanity Fair this month that William was furious his mother had done the interview and they had a blazing row about it when it was broadcast, having had to endure the toe-curling experience of watching it at Eton.)
By that point, Diana had had plenty of time to consider the spectacular fall-out from her on-air confessional watched by 22 million gob-smacked Brits.
It compelled the Queen to dramatically step in and order her and Prince Charles to divorce, cutting the Princess loose from her troubled marriage but also from the protective shield that safeguards senior members of the Royal Family.