A new trade deal with the EU could lead to restrictions on the use of the controversial weedkiller glyphosate on UK food crops.

The full-spectrum herbicide, which kills almost every plant it touches, is often sprayed on wheat, oats and other cereal and pulse crops shortly before harvest to desiccate them and make them easier to handle.

That practice has been banned in Europe since 2023 over fears of the chemical’s impact on human health. Now a wide-ranging new trade agreement with the EU could force the UK to fall into line.

Officials from the Department for the Environment, Food and Rural Affairs (Defra) are negotiating with their EU counterparts over the terms of a sanitary and phytosanitary (SPS) agreement intended to make trade with the bloc “easier, cheaper and more predictable”.

Environmental groups say the government should use the opportunity to end the pre-harvest use of glyphosate. “Phasing out glyphosate as a pre-harvest desiccant, in line with restrictions across the EU, would alleviate concerns over public health and nature, while facilitating closer trade with our European neighbours,” said the Soil Association, the Nature Friendly Farming Network, Greenpeace, the Wildlife Trusts and others in an open letter to Defra on Wednesday.

The World Health Organization classified glyphosate as “probably carcinogenic to humans” in 2015, and it has been at the centre of more than 17,000 lawsuits in the US alleging it causes cancer and other health problems. A group of experts concluded in March that “glyphosate and GBHs [glyphosate-based herbicides] cause genetic damage, oxidative stress and hormonal disruption”.

“Regulatory agencies in countries around the world should treat glyphosate and GBHs as hazardous, as some countries have started to do,” the experts said. “Agencies should act without further delay to limit their use, or eliminate them if legally required, to protect public health.”

The weedkiller remains in widespread use, however, with 41% of UK cereal crops tested between 2016 and 2023 containing residues. In 2024, 28% of samples of UK bread tested contained glyphosate.

The Soil Association’s campaigns coordinator, Cathy Cliff, said: “Experts are increasingly warning that there is no ‘safe dose’ of glyphosate, meaning the chemical should be removed from our food. Evidence of the harms linked to glyphosate has rocketed over the last decade, and we’re calling on the government to respond. It’s time to cut the chemicals from our food and fields.”

Defra did not comment on the talks with the EU when the Guardian asked about them on Tuesday but changes to the regime on glyphosate seem likely. British farmers and businesses have been told to expect changes to “pesticides and their respective maximum residue levels” and “changes to pesticide and biocide active substance approvals”.

Farmers will not be too worried. Despite the restrictions on glyphosate, the regime on pesticide use in the EU remains permissive. According to a report by the European Food Safety Authority on Tuesday, 41.6% of fruit and vegetables sold in the EU contained pesticide residues.

The talks come before the UK licence for glyphosate expires in November, precipitating a concerted push by the chemical industry for its renewal.

According to Farmer’s Weekly, the Glyphosate Renewal Group, a coalition including Bayer, Syngenta, Nufarm and others, has made a number of submissions to officials at the Health and Safety Executive, the agency responsible for licensing pesticides. It has also lobbied for exceptions to the SPS agreement that would allow for its continued use as a pre-harvest desiccant.

Awareness of the use of glyphosate in the UK food system is low, despite fears about the health impacts of exposure to chemicals in food, according to a survey commissioned by the organic food retailer Riverford, which is campaigning to end the practice of pre-harvest spraying.

According to the poll of 2,000 adults, 79% had never heard of glyphosate, but 83% were concerned about long-term exposure to chemical residues in food and 66% were “outraged” that glyphosate was used in the UK food system.

A Defra spokesperson said: “Like all pesticides, glyphosate is subject to strict regulation.”