A Welsh Labour spokesperson said the current government had taken action “to protect over 52,000 properties from flooding this Senedd term with new record levels of investment in flood protection” and passed a “landmark Clean Air Act”, and would clean up its rivers and create a new water watchdog if elected.

A Green Party spokesperson said the research showed the current government had “lost control of protecting our environment for people and nature”, and it would hold water companies to account and push for “genuine public ownership” to cut bills.

Reform UK Wales said Labour’s record “on protecting our waterways has been abysmal” and there had been little sign governments at either end of the M4 were serious about flood prevention.

A Welsh Liberal Democrat spokesperson said: “This is an emergency playing out in people’s lives” and Wales could not afford “another decade of sleepwalking towards crisis”, promising to make climate emergency a top priority, create jobs and cut energy bills.

Plaid Cymru said “environmental threats such as flooding, landslips, contaminated land, and pollution show the climate and nature emergencies aren’t remote, far-off prospects, but are affecting our ways of life in the here and now in Wales”, and said radical, urgent action was needed.

A Welsh Conservative spokesperson said: “Since Labour came into power in Westminster, Environment Agency figures show that serious water pollution incidents have increased compared with the UK Conservative Government in 2023”, adding plans for a new regulator won’t stop sewage spills or prevent water bill rises.