THAMES Water plans to raise bills by 56 per cent as it struggles with a £15.6billion debt pile.
And Southern Water is proposing an even bigger 70 per cent rise — to £749 a year after inflation.
Thames, which supplies almost ten million people, will reveal its business plan for the next five years early next week.
The firm has called for a 40 per cent increase, that’s 56 per cent once inflation is added.
It would take household water bills to an average of £733 by 2030 — around £262 more than they are currently.
The Times reported that Thames had proposed the bigger increase as part of its negotiations with Ofwat.
READ MORE THAMES WATER CRISIS
The watchdog is reviewing business plans for nine water firms and will decide whether to approve them on June 12.
Thames Water and Ofwat have been in a stand-off for the past month about its business plan.
This prompted investors in the UK’s biggest water company to refuse to put any more money in.
Shareholders declared it "uninvestable" without concessions from Ofwat.
Most read in Money
The government is making preparations in case it has to step in to support the business.