"'She certainly didn’t break the group up, the group was breaking up,' McCartney says. 'When Yoko came along, part of her attraction was her avant garde side, her view of things, so she showed him another way to be, which was very attractive to him. So it was time for John to leave, he was definitely going to leave one way or another.'
"Instead, Sir Paul points to the influence of Allen Klein – whose disputed role within the band’s business interests following the untimely death of Brian Epstein was a constant source of significant friction between McCartney and his three bandmates – as a far bigger factor in their break-up.
“'I was fighting against the other three guys who’d been my lifelong soul buddies,” he continues. “I said I wanted to fight Klein.'”
Hmmm, well Macca has a point about Klein, remember John Belushii as a Klein like figure, "I don't know where the money is, if I did I'd give it to you. I love you…" He is talking into a mirror! But they really broke up because John Lennon was sick of them"
OK, I got this story the long way a round. I got it off Life Forever, who got it from the Guardian who reported that Paul McCartney said this to David Frost. All clear??