Sir Paul's new love

Sir Paul McCartney with Heather Mills (far right) in November

Sir Paul McCartney has confirmed that he and model Heather Mills are "an item".

The former Beatle, whose wife Linda died of cancer nearly two years ago, has become close to Mills after working on a charity single with her last year.

The couple were spotted walking together in a London park, and he has appealed that they should be left alone by the media.

Sir Paul said: "Yes we're very good friends. She's a very impressive woman. We are an item."

He added: "What we don't need at this stage is photographers lurking in bushes. If this is to develop, then give us a chance.

"I'm not a politician and we're not spies. I don't want to be surrounded by photographers because that could wreck something."

Heather Mills: Fought back to health after losing her leg

Former swimwear model Mills, 32, who lost her left leg below the knee in an accident with a police motorcycle in 1993.

She met Sir Paul, 57, at a charity event a year ago. He played guitar and sang backing vocals on a single she recorded, Voice, which raised money for people who had lost limbs in war zones.

At the launch of the single in November, the two refused to pose together for photographs, and Sir Paul denied rumours their relationship was more than professional.

A few days earlier they both attended the premiere of the James Bond film, The World Is Not Enough, but arrived separately.

Mills attracted publicity in the mid-1990s for battling back to health after her accident, and devoted much of her time to helping others who had lost limbs.

She has also worked as a television presenter, and appears in a forthcoming BBC detective drama, Streetlife.

Her marriage to Alfie Karmal in 1989 was shortlived, and she was due to marry documentary cameraman Chris Terrill last summer, but the ceremony was called off with just two weeks to go.

Sir Paul is said to have only spent one night apart from Linda, who died in April 1998. The couple had been married for 29 years, and he often called her "his soulmate".

However, in October last year he spoke of how his life had "started to get a bit brighter".