The charity has published comments by the former Beatle on its peta.org.uk website, deriding the singers Lopez and P Diddy for wearing fur in spite of being sent video tapes and information over a number of years showing the harsh realities of the fur trade.
McCartney said: "Look at these videos, because you are going to see anal electrocution, you're going to see animals with their throats slit, and you are taking a beautiful animal's coat."
He also gives the message to J-Lo and P Diddy that there is no reason for them to wear fur to look more attractive because "you look good enough anyway, baby".
McCartney also recounts his disgust at meeting a man wearing a polar bear fur coat and the embarrassment of his own fur-wearing days when he was a Beatle.
This latest push by Peta follows the axing of a print ad targeting Jennifer Lopez that was due to run in US Billboard magazine in April.
It was reported at the time by the New York Daily News that Peta believed J-Lo's publicity team had put pressure on the magazine to pull the ad.
Other celebrities targeted by Peta include the model Cindy Crawford.
Previous campaigns in the UK by Peta include a print ad in April, featuring Kate Ford, who play 'Coronation Street''s Tracy Barlow, holding a rabbit with the tagline "Try telling him it's just a bit of fur trim".
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