Sir Paul McCartney is set to offer a £40 million divorce settlement to his estranged wife.

The former Beatle will pay the large sum over 20 years in return for Heather Mills' agreement that she will not speak publicly about their marriage.

A source told the News of the World: "They are thrashing out a deal which would amount to between £30 million and £40 million over 20 years and there will be strict conditions.

"Heather must reveal nothing about their personal lives - no books, no TV specials. She has one hell of a story and Paul wants a settlement to make sure it never comes out. Heather has no intention of telling it because she knows it would only hurt their daughter Bea, but it would always be lurking in the background.

"Any breach of the conditions would allow him to stop the payments - so basically he has control of Heather for the rest of his life. There's a long way to go but it looks like that will form the basis of the settlement."