Water companies threatened to hike customers' bills if the government made them clean up the sewage they dumped in rivers, openDemocracy can reveal.
One firm, which recorded profits north of £100m last year, called proposed government targets "demanding" and argued they would result in more customers struggling to afford bills.
Sewage is the main source of phosphorus water pollution in England. This drives the growth of toxic algae, which in turn kills plants and fish in rivers and lakes.