Paul McCartneyPaul McCartney has reportedly written a last love song for ex-wife Heather Mills.

The former Beatle is said to have recorded the acoustic ballad, called ‘My Soul’ for a collaboration with musician Nitin Sawhney.

Sawhney is quoted as saying: “Paul has done a track about how he feels about Heather and what was going on with the paparazzi because no one has heard his side of it at all - so this will be the first time anyone hears a song relating to that subject. It’s very emotional and a very powerful song.”

The song’s lyrics allude to Heather’s past life as a model - and the rumours that she was also an escort - and suggests that, in different circumstances and if she had been more honest about that part of her life, their marriage could have been more successful.

A source close to Paul told the Daily Mail: “What the song shows is that rather than feeling embittered towards Heather, Paul just feels sorry for her.

“He feels sorry that she was never able to tell him the full truth about her past life. He feels that their romance happened so fast and so publicly that a lot never really got said.

“Paul knows Heather is a complex person, and deeply misunderstood - but that she has hardly helped herself by being less than transparent about her life.”

The former couple finalised their divorce in May this year after it was agreed that Paul would pay Heather a £24.3million settlement. Heather is now dating holiday rep Jamie Walker after meeting in Tenerife while Paul is seeing long-time friend, New York businesswoman Nancy Shevell.