American NBC network will play the audio tapes in which Diana describes how she cut her chest and thighs with a knife and hurled herself downstairs while pregnant with Prince William, because of her unhappiness at how Charles treated her.
Diana - who was killed in a car crash in 1997 - endured comments from her ex-husband in relation to her eating disorder whilst also suffering in the knowledge of his continued affair with his now-partner CAMILLA PARKER-BOWLES.
On the tapes recorded for biographer ANDREW MORTON, Diana claims Charles failed to take her suicide threats seriously.
She says, "He said I was crying wolf. So I picked up a penknife off his dressing table and I scratched myself heavily and there was a lot of blood."
Oh her bulimia, Diana recalls an incident when Charles put his hand on her waist and said, "Bit chubby aren't we?"
Diana adds, "That triggered something in me. That and the Camilla thing. I was desperate now, desperate."
She explains how she threw herself down the stairs at their HIGHGROVE, England residence, saying, "He (Charles) said, 'I'm not going to listen - you're always doing this to me. I'm going riding now.' So I threw myself down the stairs.
"The Queen (ELIZABETH) comes out absolutely horrified - shaking, she was so frightened."18/02/2004 21:11
Take a look back at October's inaugural event.
The film is expected to continue without Mendes' involvement.