An ad that ran across various media for a plant-based burger sold by Tesco has been ruled "likely to mislead" by the advertising authority.

The ad, which ran across various media platforms, including TV, press, radio and online, did not give evidence that the Plant Chef brand of non-meat burgers would have a positive effect on the environment, despite claiming that it would, according to the Advertising Standards Authority (ASA).

The press, online and TV format of the ad featured a video or image of a woman eating a plant-based burger, with text or voiceover making such statements as: "The planet is continuing to warm... We've lowered the price of dozens of our Plant Chef products because a little swap can make a big difference to the planet".

The radio ad said that the woman was "doing her bit for the planet". In most formats in which the ad appeared, it was suggested that purchasing and consuming these plant-based products was "good for your pocket, even better for the planet".

In making its ruling, the ASA said that specific plant-based products, particularly processed products which could contain a number of different ingredients sourced from around the world, could contain ingredients or be produced and transported by methods that have high carbon or negative environmental impacts.

The advertising watchdog noted that claims of environmental benefit must be based on the full life cycle of the product.

"It would not necessarily always be the case that specific plant-based products would always be guaranteed to have a lower carbon or environmental impact than specific meat-based products," the ASA said.

"Because we considered the ads implied that switching to products in the Plant Chef range would positively affect the environment, we expected to see evidence that that was the case based on the full life cycle of the Plant Chef burger in comparison with a meat burger."

For these reason, the ASA concluded that the claims regarding the positive benefits of this range of products for the environment "had not been substantiated and were likely to mislead".

It was found that the ad breached rules concerning misleading advertising and environmental claims.

The ASA directed that the ad must not appear again in its current form on these media platforms.

Tesco was instructed to ensure that, in future, it "did not make environmental claims about its products unless it held sufficient evidence to substantiate the claims".