Disgust over litter, outrage at potholes and pledges to support jobs are all hallmarks of local council election literature. But on yellow leaflets up and down the country, the focus is likely to centre more on the state of local rivers.

Adam Vaughan www.thetimes.co.uk

Tory voters are so angry about the state of polluted rivers that the issue could even cost the Conservatives the next general election, according to Sir Ed Davey, the Liberal Democrat leader.

Davey, who was energy and climate secretary during the coalition years, headed to swing seats in Lewes and Eastbourne in Sussex last week to promise tougher action on sewage.

“We think that a lot of Tory voters are very, very angry. We think this could lose huge numbers of Tory seats to us at the council elections, and be a big issue in our fight for the general election,” Davey said on the day the government announced its “plan for water”.

A Lib Dem election leaflet doing the rounds in Lewes homes in on local environmental concerns

As well as visiting Eastbourne to see the beach’s storm overflows — the relief valves that nationally released raw sewage for 1.7 million hours last year — Davey also went to the River Ouse in Lewes. The district council recently passed a motion to give the Ouse legal rights, as concern grows about pollution of waterways.

While refusing to put a number on how many seats water pollution could swing, Davey said the Lib Dems were campaigning on the issue in Sussex, Winchester, Cheltenham, and Chesham & Amersham. “It’s not impossible to think that whether we get rid of the Conservative government or not may depend on people’s response on these environmental issues,” he said.

Davey said river health had resonated with voters in ways that some environmental issues had not. “They know their local river or their local beach. They swim in there or their kids swim in there, or they fish in there, their dogs go in there. It’s part of their life,” he said. In some constituencies, including Lewes, candidates have made water pollution the focus of their leaflets.

The Lib Dems have made sewage pollution one of their big issues since gaining traction on the problem at the 2021 by-election in Chesham & Amersham, Buckinghamshire, won by its candidate Sarah Green. “We suddenly realised that what we thought was a local issue was actually a national issue,” Davey said. Everyone asked what he was doing when he posed in the River Chess with wellington boots, Davey said, but the issue proved to be salient.

Davey was critical of the environment secretary Thérèse Coffey’s plan for waterways. He noted that her pledge to ban plastic wet wipes had been made several times before, including five years ago by Michael Gove. The Lib Dem leader blamed “a big political failure to direct regulators including Ofwat and the Environment Agency to get tough on water companies”. Although the Environment Agency budget rose last year, it had fallen for years and staff morale there has plummeted because of low pay.

Water companies are not off the hook, however. “It appears to me from some of the things I’ve seen that many of them are breaking the law and knowingly breaking the law,” Davey said. “They are discharging sewage at times when they shouldn’t and they have not been permitted to do so.”

It should not take decades to clean up our rivers, he said, citing Lib Dem policies including a tougher water regulator and environmental experts on the boards of water companies. Davey said water pollution was a “very personal” issue for him because he read books by the environmentalist Jonathon Poritt in the 1980s and joined the Lib Dems in 1989 because Paddy Ashdown and Simon Hughes were talking about the environment.

The government confirmed on Monday that four new bathing sites would be designated at wild swimming spots: two at Rutland Water, one on the river Deben in Suffolk and one at Firestone Bay in Plymouth. This should ensure that regular monitoring and health checks are carried out on the water. However, applications for bathing water status on at least seven rivers, including another stretch of the Deben, were rejected.