Mccartney, 70, is plotting to return to the studio with Lynne and complete work on another Lennon tune which he and his Beatles bandmates gave up on while recording 'Free As A Bird' for the group's anthology project, reported Contactmusic.
The rocker has fond memories of working with Lynne on the Beatles best of, but he regrets not challenging the late George Harrison over a forgotten track that featured Lennon's vocals.
"There was another one (track) that we started working on but George went off it... We were like, 'No George, this is John'. He said, 'It's still rubbish!' 'Ok then'.
"So that one (track) is still lingering around. I'm gonna nick in with Jeff and do it, finish it, one of these days," he said.