The Sunday Mirror reports that the ad will be shot this week, and will have a 1930s feel to it. Advertising for Walkers Crisps is handled by Abbott Mead Vickers BBDO.
News that Walkers has signed up another star to endorse its crisps will enrage pressure groups, who have been highly critical of Walkers' 11-year ad campaign starring Lineker and say that celebs should be banned from junk food advertising.
Church is just the latest in a long line of leading ladies to appear alongside the former England footballer. Others to have starred in ads include Victoria Beckham, Tara Palmer-Tomkinson, Kate Winslet and the model Helena Christensen.
From the world of sport, the likes of Paul Gascoigne, Bobby Robson, Terry Venables and Steve Redgrave have also appeared.
Only last month, Walkers trumpeted the reformulation of its crisps with an oil containing less saturated fat in a series of ads in which Lineker dropped his no-more-Mr-Nice-Guy persona to talk about the new recipe.
But reports say that this new campaign with Church will mark a return to humorous spots.
Church became famous as a child singer performing popular classical music, but last year released her first pop record 'Tissues and Issues'. She appears reticent to dip her toes in the world of commercial endorsement, having reportedly turned down an offer to promote Wonderbra.
However, she is the latest celebrity to get involved in the restaurant business, following in the footsteps of the likes of Robert de Niro and Michael Caine, by buying an establishment called The Post Office in Cardiff.
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