Campaigners are calling on Sir Keir Starmer to take action to end the 'poisoning' of rivers, including from raw sewage and agricultural waste.
A central London protest has been organised for 26 October by numerous environmental organisations to highlight the 'alarming' water pollution crisis.
The March for Clean Water, which is timed to mark the end of the first 100 days of the new government, will also involve well-known personalities, including river campaigner Feargal Sharkey.
They warn that pollutants - including from agriculture - have been allowed to leave most waterways "so filthy that they present major risks to human health and untold damage to nature."
Water companies have also been blamed by campaigners for "continuous illegal dumping of raw sewage".
River campaigner Feargal Sharkey said the government must order a review of the "failed" oversight and regulation of the water industry.
He said: "We call on the government to end the environmental devastation being inflicted upon our rivers, lakes and seas.
"It is now time to hold to account those industries that for too long now have been allowed to knowingly and wantonly pollute our waters driven by nothing more than profit and greed.
"We call on everyone in the country who is concerned or angry at the state of our waters to join us and march.”
The March for Clean Water is coordinated by River Action and Feargal Sharkey in collaboration with numerous environmental organisations, including the Soil Association.
Founder of River Action, Charles Watson, said agricultural run-off was also an issue for the UK's waterways.
He said: "The initial noises coming out of our new government regarding cleaning up our filthy waterways, whilst encouraging, do not nearly go far enough to deal with the scale of the problem they have inherited.
"Nothing short of wholescale reform of our failed regulatory system and comprehensive strategies to address all major sources of pollution, including sewage discharges and agricultural run-off, will suffice.
"On 26 October the public will make this point very clear to Sir Keir Starmer in no uncertain terms.”
