The United Kingdom’s advertising regulator has banned ads from , and that described their clothing as “sustainable,” after finding insufficient evidence to support the claims.

The adverts — placed via Google — used phrases such as “sustainable materials,” “sustainable style,” and “sustainable clothing,” which the regulator ruled were vague absolute assertions lacking the robust proof required under UK advertising standards.

In each case, the companies failed to provide substantiation showing their garments had a negligible environmental impact over their full life-cycle.

The watchdog emphasised that legitimate environmental claims must be clear, precise and underpinned by strong, verifiable evidence — a threshold not met in the banned ads.

Nike argued that its reference to “sustainable materials” was intended broadly and highlighted other products using recycled fabrics, but the regulator found no qualification pointing to those specific items.

Superdry contended its ad suggested only certain products might combine style with sustainability — yet the claim still implied a broader environmental quality.

Lacoste acknowledged the difficulty of proving that clothing was fully “eco-friendly,” and pulled the ads.

The rulings reflect growing enforcement from regulators under new guidelines that hold businesses to account for blanket environmental statements.

Previously, several major retailers had already been warned or sanctioned under wider green-claims scrutiny, and the latest decisions reinforce that fashion brands must provide transparent data or risk further sanctions.

For UK consumers, the bans represent a push toward greater honesty and clarity in marketing — forcing brands to back up environmental aspirations with real-world facts rather than marketing rhetoric.