Sir Paul McCartney reforms the Beatles in his dreams.

The 76-year-old singer has admitted that he often thinks about the iconic band and remembers late members John Lennon and George Harrison ''with a lot of sadness'', as he insists they should both ''still be here''.

In an interview with BBC Radio Scotland - which is due to air on December 29 - he said: ''John and George are still a big part of my life, always will be.

''It would have been great to get the Beatles back together again. People always say what if? But we can't, so, sadly, that's not going to happen.

''I often think about them with a lot of sadness, because they should still be here. In John's case, it was a terrible thing. In George's, a terrible illness.

''If by some strange fluke it was to happen, it would be beautiful.

''As a musician, you often have dreams about being in the studio or on stage, so I'm often with the guys.

''Just the other morning, I woke up and I was with George. And that was very nice. I think of George as my little mate - he was the youngest in the group.

''That's how I run into John and George these days. So the Beatles have re-formed - in my head.''

George passed away on November 29, 2001, after a battle with lung cancer while John was assassinated outside his Manhattan apartment by Mark David Chapman in 1980.

The 'Hey Jude' hitmaker went on to explain that although he is deeply saddened by the passing of his bandmates, he's grateful to have known them.

Paul added: ''Even though there is sadness, the main thing is the joy of knowing those two guys. I miss them a lot.''