Britain’s beekeepers are at war over their association’s endorsement for money of four insecticides, all of them fatal to bees, made by major chemical companies.

The British Beekeepers’ Association has been selling its logo to four European pesticide producers and is believed to have received about £175,000 in return.

The active ingredient chemicals in the four pesticides the beekeepers endorsed are synthetic pyrethroids, which are among the most powerful of modern insect-killers.

The deal was struck in secret by the beekeepers’ association executive without the knowledge of the overwhelming majority of its members.

After news of the deal emerged, some members expressed outrage and others resigned.

The beekeepers have now said they will end their pesticide endorsements – but have left the door open to future deals with agrochemical companies.

The battling beekeepers will have a showdown this weekend at the National Beekeeping Centre at Stoneleigh in Warwickshire.

An open letter signed by prominent figures in the world of the environment and agriculture condemns the British Beekeepers’ Association for its commercial relationship with the German chemicals giants Bayer and BASF, the Swiss-based Syngenta and the Belgian firm Belchim – and demands that it permanently sever commercial links with agrochemical companies.

“A charity that claims to have the interests of bees and beekeeping at heart should never put itself in a position where it is under the influence of corporations whose purpose is to sell insecticides which are able to kill bees,” said Philip Chandler, a Devon beekeeper and one of the organisers of the open letter, which has been signed by the botanist David Bellamy, the author and television wildlife presenter Chris Packham and Lord Melchett, policy director of the Soil Association, the organic farming body. “It is the equivalent of a cancer research charity being controlled by a tobacco company,” Mr Chandler added.