According to a Reuters newswire story, European Union countries backed a proposal on April 27 to ban all use outdoors of insecticides known as neonicotinoids that studies have shown can harm bees.

The ban, championed by environmental activists, covers the use of three active substances — imidacloprid, developed by Bayer CropScience; clothianidin, developed by Takeda Chemical Industries and Bayer CropScience; and Syngenta’s thiamethoxam.

“All outdoor uses will be banned and the neonicotinoids in question will only be allowed in permanent greenhouses where exposure of bees is not expected,” the European Commission said in a statement.

Representatives of EU member states in the EC’s standing committee on plants, animals, food and feed on Friday supported the proposal for a new regulation to be adopted by the EC “in the coming weeks” and applicable “by the end of the year.”

Bayer called the ban “a sad day for farmers and a bad deal for Europe” and said it would not help bees. Many farmers, it said, had no other way of controlling pests and that the result was more spraying and a return to older, less effective chemicals.

The use of neonics in the European Union has been restricted to certain crops since 2013, but environmental groups have called for a total ban and sparked a debate across the continent about the wider use of chemicals in farming.

Both Bayer and Syngenta have challenged the 2013 partial ban at the European Court of Justice. A verdict is due on May 17.

Bayer, in a separate move, announced it would sell its clothianidin-based seed treatment brands Poncho and VOTiVO to fellow German chemical firm BASF.

The brands are part of a $2.65 billion asset sale to help clear the regulatory path for Bayer’s planned takeover of seed and ag chem firm Monsanto.

Canadian growers await the decision, expected later this year, from the Pest Management Regulatory Agency on two insecticides:  clothianidin and thiamethoxam.