Blue Diamond, Notcutts, Hillier, SCATS, Scotsdales and Squires have joined a campaign to eradicate pesticides containing chemicals linked to bee decline, bringing several high-profile garden manufacturers into the firing line.

The garden businesses are following the example set by B&Q, Wickes and Homebase, who pulled the products from their shelves last month.

It comes after the European Food Safety Authority (EFSA) linked some of the most widely-used neonicotinoid insecticides to declining bee health.

The EU proposed a ban on using the insecticides on flowering crops earlier this month, which would mean the chemicals are forbidden from use on corn, oil seed rape, and sunflowers among other crops across Europe for two years. The UK government responded by saying it was against such a ban due to a lack of scientific evidence.

Bayer has been named by several campaigners as one of the manufacturers supplying potentially harmful insecticides. In a statement, the supplier called the European Commission's proposal "draconian" and said: "We believe that the commission's overly conservative interpretation of the precautionary principle is a missed opportunity to achieve a fair and proportional solution.

"Bayer CropScience shares the concerns surrounding bee health and has been investing heavily in research to minimise the impact of crop protection products on bees and in extensive stewardship measures supporting the responsible and proper use of its products.

"We continue to believe in the responsible use of neonicotinoid-containing products which have been used for many years and are vital to European farmers."

Bayer added a warning that any "disproportionate action" on the part of the EU would "jeopardise the competitiveness of European agriculture and finally lead to higher costs for food, feed, fiber and renewable raw materials and have an enormous impact throughout the whole food chain."

The HTA, too, has said the products are safe, stating: "The HTA shares the UK government view that there is no scientific evidence that the correct use of neonicotonoids is harmful to bees. Recent publicised research has done nothing to change this view.

"Like the UK government, we believe the existing stringent regulatory controls provide sufficient guarantees against the dangers to bees from the use of these products. And like the government, we will oppose any proposals to ban their use until scientific opinion determines another course of action."

The association has issued an information sheet on neonicotinoids, which points out that neither the amateur British Beekeeper Association and professional Bee Farmer Association, nor UK bee scientists have called for neonicotinoids products to be withdrawn. The information also details which pesticide products containing the chemicals have been authorised for use in the UK, naming Bayer, Westland Horticulture and The Scotts Company among others.

The GCA, meanwhile, has also taken a stand alongside the HTA. Chairman Peter Burks said: “At present there is no evidence that using neonicotinoid insecticides will harm bees. It is my understanding that the BBA is far more concerned with the Varroa mite and some people have said that if there wasn’t such a huge problem with mites that the question regarding insecticides may not have been raised.

“If we advised our members to take neonicotinoid insecticides off their shelves there would be virtually no insecticides left to sell. We are just asking them to read the HTA’s information sheet and to be aware of the controversies surrounding the issue.

“We’ll be closely following the latest developments in research into this topic as we are committed to helping protect bees, promote conservation and support wildlife, and will keep our members updated.”

On the other end of the battle field, Friends of the Earth is campaigning for the Prime Minister to commit to a 'National Bee Action Plan'. The association's head of campaigns Andrew Pendleton said: "We're delighted stores are withdrawing these pesticides. Other retailers must follow suit and take action to protect our bees.

"It's also good news that Europe is following the latest scientific advice on bees and chemicals. The UK government should support the new laws."

The neonicotinoid insecticides which the EFSA has linked to bee decline are imidacloprid, thiamethoxam, and clothianidin. The Soil Association has also warned against acetamiprid and thiacloprid, which are neonicotinoids containing less toxicity. There is conflicting evidence on whether these latter ingredients can be harmful to bees.

DIYWeek.net will have more on this story as it develops.