Fans of the brand are being asked to photograph the contents of their bags and share the results, using the hashtag #totesbig or #totessmall, depending on their chosen style.
Celebrities including Jools Oliver, Jo Whiley (pictured) and Sophie Ellis Bexter have signed up to the campaign.
Photos of what they keep in their favourite designs will be revealed at an exhibition at 180 Piccadilly, which will be open to the public for two weeks from Thursday 21 August.
The exhibition includes a specially-created “Illusion Room”, where visitors will appear either huge or tiny, depending on where they stand. The room will travel around the country until the end of September, after the exhibition ends.
And for the record, here at BR we like our #totesbig.