A Walkers packet of Cheers and Onion crisps during the UEFA Champions League Round of 16 second leg match between Leicester City and Sevilla FC at The King Power Stadium on March 14, 2017 in Leicester, United Kingdom.
Catherine Ivill - AMA/Getty Images
September 27, 2018 9:00 AM EDT

The postal service in the United Kingdom has asked members of the public to stop mailing potato chip bags after a social media campaign resulted in a surge of chip packages, causing messy delays.

The movement which was launched on Friday, asked activists to post pictures of themselves sending their empty bags back to the manufacturer, Walkers. It’s an effort to pressure Britain’s largest potato chip brand to stop packaging its products in plastic.

The company has a mailing address that allows people in the U.K. to send them letters free of charge, so the campaign’s website advertised that it “won’t cost a penny” for people to send their chip bags. Protesters were asked to merely put a label with Walkers’ address on the packet.

Although Walkers plans to produce plastic-free packaging for the 11 million daily bags of chips the company produces by 2025, campaigners believe this is too long a wait. A petition in conjunction with the campaign, which has over 300,000 signatures, demands the company owned by PepsiCo “change the materials for their packets to one which is recyclable or even more preferably a non-plastic environmentally friendly material.”

U.K. law states that its national mail service must deliver post if it is properly addressed, but the Royal Mail has encouraged those involved to at least use an envelope.

Contact us at letters@time.com.

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