It seemed like a wonderfully subversive idea at the time. An album cover with the Beatles as butchers, complete with raw meat and decapitated plastic babies.

John Lennon thought it was a hoot, and would dispel the band's clean and chirpy image. However, George Harrison thought it was sick.

The Beatles' famous butcher cover went out on their 1966 American album Yesterday and Today but was quickly withdrawn after the horrified reaction of retailers and radio stations.

Rather than pulp the covers, the record company pasted another picture of the band around a luggage trunk on to the butchers cover.

As news of this spread, fans tried to peel off the new cover, with varying degrees of success.

The photographer Robert Whitaker has lent the National Portrait Gallery in London a print of his original photograph for an exhibition on the Beatles which opens on Wednesday.

"This is the first time we've done a show on a pop group," said curator Terence Pepper. "The cover came out in the US for two days and they defended it as an example of pop art."

About 60 pictures make up the exhibition, including 10 by Linda McCartney, which have been selected and lent by Sir Paul McCartney.

There are also early images by Astrid Kirchherr, the girlfriend of Stuart Sutcliffe who helped to style the band's mop tops.

Previously unseen pictures by Michael Ward will be on show - he spent a day with the band after being commissioned by the magazine Honey, but his editor lost interest so some were undeveloped.

One guest expected to attend the opening will be Fiona Adams, who will be travelling from Jersey.

She has now been identified as the uncredited photographer who took the cover picture of the Twist and Shout EP with John, Paul, George and Ringo leaping into the air.

The exhibition coincides with the first major retrospective devoted to the portrait photographer Angus McBean, who also took defining images of the Beatles at the start and end of their careers.

· Beatles on the Balcony runs from next Wednesday until October 22 at the National Portrait Gallery.