The chemicals are widely used in UK agriculture but have been banned as a precaution in four other European countries. Last week the Italian government issued an immediate suspension after it accepted that the pesticides were implicated in killing honeybees, joining France, Germany and Slovenia.
Peter Melchett, the Soil Association's policy director, said: "It is typical of the lax approach to pesticide regulation in the UK that we look like being one of the last of the major farming countries in the EU to wake up to the threat to our honeybees."
The pesticides, known as neonicotinoids, are approved to kill insects on a range of crops in the UK including oilseed rape, barley and sugar beet. Their use on oilseed rape is of particular concern to beekeepers as the crop's yellow flower is very attractive to honeybees.
Germany suspended sales of the pesticides in May after 700 beekeepers along the Rhine reported that two-thirds of their bees had died following the application of clothianidin. In France, imidacloprid has been banned on sunflowers since 1999 and as a sweetcorn treatment since 2003, after a third of honeybees were wiped out. The Soil Association is calling on the environment secretary, Hilary Benn, to ban the pesticides in a letter sent today.
Imidacloprid and clothianidin are produced by a division of the chemical manufacturer Bayer. Imidacloprid is its bestselling pesticide and is used in 120 countries. Bayer has always maintained that neonicotinoids are safe for bees if correctly applied. "Extensive internal and international scientific studies have confirmed that neonicotinoids do not present a hazard to bees," Utz Klages, a spokesman for Bayer CropScience, said recently.
The National Farmers' Union said it was opposed to any ban on pesticides. Paul Chambers, NFU plant health adviser, said: "Banning pesticides using the precautionary principle is not based on good science. Pests and disease are the problems facing honeybees in the UK. The government needs to put more money into researching honeybee health."
The Department for the Environment, Food and Rural Affairs also attributed the decline in honeybee populations to a variety of factors. A Defra spokesman said: "There are no plans to ban pesticides."
Beekeepers worldwide have reported catastrophic losses of from 30% to 90% of their honeybee colonies during the last two years. Two-thirds of all major crops rely on pollination, mainly by honeybees.
At Claines Canna we have been monitoring the pollinators feeding on the Canna collection, and in the vegetable plot, and we are of the opinion that the majority of pollinators this year have been bumble bees and wasps.