Defra breached law when it let farmers use bee-killing pesticide, watchdog says

On teaspoon of thiamethoxam, the active ingredient in the pesticide Cruiser SB, is enough to kill 1.25bn honeybees. Photograph: Ben Birchall/PAView image in fullscreenOn teaspoon of thiamethoxam, the active ingredient in the pesticide Cruiser SB, is enough to kill 1.25bn honeybees. Photograph: Ben Birchall/PADefra breached law when it let farmers use bee-killing pesticide, watchdog saysOffice for Environmental Protection finds failures by department when it granted emergency authorisation in 2023 and 2024

The UK government breached environmental law on several occasions when granting farmers permission to use a bee-killing pesticide, a watchdog has found.

In 2023 and 2024, the Department for Environment, Food and Rural Affairs (Defra) in the then Conservative government granted emergency authorisation to allow farmers to use a banned neonicotinoid pesticide on sugar beet crops.

The pesticide, Cruiser SB, contains the active ingredient thiamethoxam. One teaspoon of this is enough to kill 1.25bn honeybees, according to Prof Dave Goulson, a bee expert at the University of Sussex.

After a complaint by the campaign group ClientEarth, the Office for Environmental Protection (OEP), which was set up after Brexit as England’s environmental watchdog, launched an investigation into “possible serious failures” by Defra.

The OEP has now concluded there were failures to comply with environmental law on four occasions. These include a failure to consider the authorisation’s impact on protected sites, and to understand, avoid or mitigate the known risk of harm to those sites.

Dr Doug Parr, the chief scientist and policy director at Greenpeace UK, said the “absolutely shocking neglect from past governments would have had “deadly ramifications for our beleaguered wildlife”.

Since the launch of the OEP’s investigation in July 2024, the government has pledged to ban emergency authorisations for three banned neonicotinoids.

Not all neonicotinoid pesticides are banned. The government recently granted an emergency authorisation to allow farmers to complete a second spray of the neonicotinoid pesticide Insyst SG to control peach-potato aphid on sugar beet crops.

Parr said the government should now “ban all pesticides of this kind” and give farmers the “urgent support they need to move away from these chemicals and towards nature-friendly farming methods”.

In response to the OEP’s findings, Defra has proposed to update the assessment process for granting emergency authorisations so that it expressly recognises the relevance of potential impacts on protected sites.

Kyle Lischak, the head of ClientEarth UK, said this announcement was a “huge step forward”.

However, Jenna Hegarty, the head of UK policy at the Nature Friendly Farming Network, said the findings could damage confidence in the government’s commitment to the transition to environmentally friendly farming.

She said: “It’s great we have the safeguards in place to catch this but for a sector that has had its trust shaken, to see the failure by the government to do things properly, I think it’s not going to engender the confidence we really need to see rebuilding in the sector.”

The OEP will monitor the implementation of the updated process, which it said was due to be in place by November 2026.