Councillors have agreed to write to the Secretary of State calling for urgent measures to be put in place following reports of dangerous levels of powerful insecticides in the River Waveney.

The River Waveney and River Wensum were two of eight rivers across England found to be heavily contaminated with neonicotinoid pesticides in tests conducted by the Environment Agency last year, placing aquatic insects, fish and birds at risk.

The Waveney was found to be acutely polluted while the Wensum, a Special Area of Conservation for its river life, was found to be chronically polluted.

Graham Elliott, Green Party councillor for Beccles North, submitted a notice of motion about the issue to be discussed at a meeting of Waveney District Council last week.

His motion received almost unanimous support, with councillors agreeing to write to the Secretary of State to urge that there is regular and systematic testing of neonicotinoids in rivers to monitor levels and the impact of the pollution. They are also calling for a total ban of neonicotinoid use both outdoors and in greenhouses as soon as possible, and are urging that even before such a ban comes into force, better information is given to farmers and growers who are responsible for their use about the levels of these pollutants in waterways.

Mr Elliott said: “The River Waveney is one of the jewels of this area. It is a very significant resource for local people for recreation and leisure but also for tourist as well, but it’s not good for tourism if people think our beautiful river is polluted.

“But it’s all superficial compared to the danger its causing to aquatic life, which we know is significant.

“The problem is we don’t really know enough about it so two-thirds of the motion is asking for more information urgently.”

Due to the harm they cause to bees and other pollinators, neonicotinoids were banned in 2013 by the European Union from use on flowering crops.

A vote to extend the ban to all outdoor uses is expected soon.

Tests for neonicotinoids in British rivers, mandated by the EU, were conducted last year and the results were released by Buglife, which is devoted to the conservation of invertebrates.