Water companies across England and Wales are asking for bills to be made even higher than they first requested, with one company seeking an 84% hike.
The biggest water company in the UK, Thames Water, is now looking for bills to rise 53% and cost £667 a year by 2029/30, according to figures published by water regulator Ofwat.
It would make them the most expensive water bills in the country.
The biggest rise - 84% - is sought by Southern Water.
Of all eleven English and Welsh water and wastewater firms only one utility, Wessex Water, is not seeking even higher bills than they first requested from the regulator in July.
Money blog: Wine drinkers face price increase with new tax system - some favourites may disappear
Ofwat will make its final decision for how much water bills can rise on 19 December. Its interim decision, made in July, said the average bill could rise 21% a year.
On average the companies want bills to rise 40% and cost £615 a year by 2030, compared to the current average bill of £439 a year.
The rise comes as the government announced increased regulation on firms and three companies were hit by Ofwat with hundreds of millions of fines. It was these demands that necessitated pricier bills, the companies told Ofwat.
Under government proposals, water company executives could face prison time for failing to cooperate or obstruct investigations and be banned from taking bonuses. Greater compensation payments to those affected by contaminated water have also been proposed.
Companies also have to have their spending and investments approved by Ofwat.
But the regulator said it "made it clear that companies needed to provide better evidence" to justify high spending allowances to show the proposed schemes were efficient, the best option and required.
(c) Sky News 2024: Water companies seek even higher bill increases than first indicated
Chris Kaba was 'core member' of gang and 'gunman in nightclub shooting' days before he was killed by police
Paul Gascoigne's daughter says she was groomed and sexually assaulted by Al Fayed
Wales train crash: Passenger dead and 15 in hospital after collision in Powys
Assault, screaming and sensory overload: Inside HMP Elmley where 'every day is unpredictable'
King confronted by indigenous activists day after being heckled in Australian parliament
US election: The Arab-Americans turning to 'wild card' Trump in Michigan
Harvey Weinstein has rare bone marrow cancer and is treated in prison
Ely riots: Defendants enter pleas over alleged disorder
Liam Payne: Singer had cocaine in his body at time of death, official says
