The government has lifted an EU ban on "dangerous" pesticides linked to the decline in bees, despite a petition from more than half a million people protesting the move.
Farmers will be allowed to use the two neonicotinoid pesticides on their oilseed rape crops for the next 120 days, even though the chemicals have can "seriously harm" the insects.
According to the Soil Association, which campaigned for the ban, neonicotinoids block neural pathways in insects' central nervous systems. The chemicals impair bees' communication, homing and foraging ability, flight activity, ability to discriminate by smell, learning, and immune systems - all of which have an impact on bees' ability to survive.
Since the start of the 21st century, two species of bee have become extinct in the UK, while other types are sharply declining, partly thanks to the use of pesticide.
Europe has seen a sharp decline in bee numbers
A spokesperson for the National Farmers' Union expressed their support for the temporary reprieve.
"The NFU has worked relentlessly to submit a robust application and we're glad to finally see a positive result. However, we know that this isn't enough - flea beetle threat is a widespread problem on a national scale and the extremely limited nature of this authorisation is unfortunately not going to help the vast majority of farmers in need of the protection."
Others, however, are furious the government has bowed to pressure.
Friends of the Earth bees campaigner Paul de Zylva said: "It's scandalous that the government has caved in to NFU pressure. Ever more scientific evidence shows just how dangerous these chemicals are to bees and other pollinators."
Barry Gardiner, Labour's shadow Defra minister, added: "I have written to environment secretary Liz Truss challenging her to release whatever scientific evidence she considers could possibly justify this decision. Public confidence cannot be maintained if she refuses."
Neonicotinoids are a relatively new type of insecticide, which have been brought in during the past 20 years to control pests, particularly those feeding on cereal crops.
Once distributed, the chemicals remain active in plants for weeks, and are absorbed into the flowers, leaves, roots and even the plant's pollen and nectar.
Tom Pashby, campaigns officer for the Young Green Party, told HuffPost UK: "The Conservative Government's failure to uphold the EU ban on neonicotinoid pesticides is completely unacceptable.
"It is an incredibly short sighted move which puts the future health of our bees, wildlife and consequently our food supply at risk. We stand in solidarity with campaign groups that have been working tirelessly to pressure the Government into making the correct decision."
The petition, which has reached 508,000 signatures at the time of publication, addresses Elizabeth Truss , the secretary of state for environment, food and rural affairs, pleading with her to revoke the lift.
"Please don't allow any exemptions to the European ban on bee-killing pesticides (known as neonicotinoids)," the petition reads. "Our bees are too important."
A 2013 study by the food and environment agency (Fera), which suggested neonicotinoid pesticides do not threaten bees, made the basis for the government's decision to lift the ban. However, recent reanalysis of the same research found the pesticide had reduced the numbers of queen bees.
Dave Goulson, a biology professor at Sussex University, said: "The conclusions [Fera] come to seem to be completely contrary to their own results section.
"They find that 100% of the time there is a negative relationship between how much pesticides were found in the nest and how well the nest performed, and they go on to conclude that the study shows that there isn’t a significant effect of pesticides on bee colonies. It doesn’t add up."
In another twist, the government was also found to have gagged its pesticides advisers, after the Expert Committee on Pesticides refused to back farmers' requests to lift the ban.
A Defra spokesperson said: "We make decisions on pesticides based on the science only once the regulators are satisfied they are safe to people and the environment. Based on the evidence, we have followed the advice of the ECP and our chief scientist that a limited emergency authorisation of two pesticides should be granted in areas where oil rape crops are at greatest risk of pest damage."