Owen Paterson has written to water company chiefs urging them not to add huge inflation-busting increases to their bills.
The Environment Secretary told water firms in his letter that it was "crucial" to keep bills affordable. Households are bracing themselves for a 3.5% rise in water bills next year, which would leave them paying £388 more from April 2013 to March 2014.
Rising energy prices have also caused controversy over the last few weeks, with Ed Miliband warning today that ordinary Britons have been suffering in a "cost of living crisis".
Paterson urged water firms to introduce "social tariffs" for vulnerable customers, adding: “We know household budgets are under pressure and keeping water bills affordable is a crucial way we can help hardworking people.
“That is why we are pressing hard to make sure customers get a fair deal by encouraging water companies to look closely at any price increases.”
A Whitehall source described Paterson's letter to water companies as a "shot across the bows".