For Linda: Paul McCartney records a song for his late wife's vegetarian food advert

Sir Paul McCartney has recorded a song to accompany a new TV advert for his late wife Linda's vegetarian food range.

The advert, to be screened next week, will feature an animated version of Linda, who died in 1998. The frozen food firm which Linda launched has not advertised on television for 15 years.

It is thought to be the first time Sir Paul has specifically recorded a tune for an ad, although his songs were made available for licensing to commercials several years ago.

The advert is narrated by Sir Paul's friend, Elvis Costello, who has been a vegetarian since the early 1980s.

Costello said: "Linda always talked well and made it seem that you wouldn't be joining a secret weird society by being vegetarian."

The ad has been created by a team which has worked on animated projects for The Beatles and Gorillaz and features Linda walking her children to a woodland feast.

Fans will be scouring the footage for references to Sir Paul. An image of a sheepdog makes several appearances and could be the dog immortalised in his Beatles tune Martha My Dear, while one figure bears a resemblance to the Fab Four's roadie Mal Evans.

There is also a musical frog which could be a nod to Sir Paul's top three hit, We All Stand Together with The Frog Chorus.

The song which accompanies the "LoveLinda" campaign ad is a re-recorded version of his song Heart Of The Country, which appeared on 1971 album Ram. It went on to be the B-side of his single The Back Seat Of My Car. The new version was done during a session with producer Mark Ronson.