The letter was penned shortly before The Beatles split up in 1970...

A private letter written by JOHN LENNON to PAUL McCARTNEY is set raise £70,000 when auctioned by CHRISTIE’S later in the year.

According to this morning’s Independent newspaper (August 6), the letter, written before The Beatles split in 1970, criticises McCartney‘s late wife Linda as a “middle-aged, cranky fan”, as well as defending his own relationship with Yoko Ono.

The six-page letter was written at Tittenhurst Park, Lennon‘s mansion, and also implies that McCartney‘s fame has gone to his head.

He wrote: “Do you really think most of today’s art came about because of The Beatles? I don’t believe you’re that insane. Didn’t we always say we were part of the movement, not all of it? Get off your gold disc and fly.”

The letter is also said to reveal that the band had effectively split before the official announcement.

The letter is being auctioned by an anonymous vendor who bought it in the early 90s.