Mills has posed for a poster for the Viva! campaign, headlined: "Hey, Meaty, you're making me so hot!"

Meanwhile, McCartney, 65, threw his support to a campaign to prevent the closing of a post office in Lower Heswall, 3 miles southwest of Liverpool, near one of his homes.

"This village post office is a vital part of local community life and as such should be saved for future generations to cherish. Its 100-year history should not be cast aside lightly," the ex-Beatle said in a message read outside the post office by his brother Mike.

Mike McCartney signed a "save the post office petition" twice — once for Paul and once for himself.