GARDEN centres are being urged to withdraw products which contain a type of pesticide linked to bee declines.

In its latest product guide, Ethical Consumer magazine said that nine of the UK's leading garden centres including B&Q and Homebase were selling Provado Ultimate Bug Killer which contains a neonicotinoid chemical known as thiacloprid.

Environmental campaigners say that while thiacloprid is less toxic to bees than three other neonicotinoid pesticides which have been banned for use on crops attractive to honey bees, there is growing evidence the chemical harms the pollinating insects.

B&Q, Blue Diamond, Dobbies, Hilliers, Homebase, Notcutts, Squires, Wilko and Wyevale are all stocking the bug killer that contains the chemical, Ethical Consumer said.

Jane Turner, co-researcher on the Ethical Consumer product guide to garden centres, said: "Gardeners will be shocked to discover that by using these insecticides they are unwittingly introducing dodgy chemicals into their gardens which are being increasingly implicated in the crisis facing our honey bees.

"We call on all garden centres to ensure that they don't sell any products that could harm our bees."

Three neonicotinoids have been banned for two years by the EU from use on crops attractive to honey bees and garden use, over concerns they may damage the insects' ability to forage and navigate - although the UK government opposed the move.

More recent studies have suggested the chemicals could be playing a role in declines of others species, including butterflies and farmland birds.