Ed Miliband has pledged to introduce new social tariffs in the water industry in a bid to drive down living costs.
Speaking in Battersea, Mr Miliband attacked the Government on the issue of the cost of living crisis and vowed to "stand up for markets that work for working people".
Mr Miliband said the water industry should be "scrutinised to make sure it is working properly", during an interview with the Evening Standard last week.
The water industry is the latest sector to be scrutinised by the Labour leader after he promised to freeze gas and electricity bills until 2017 if his party won the next general election.
"Something has gone really wrong" in the UK energy market and Parliament has to "tackle that", the shadow energy secretary told Daybreak.
Labour's Caroline Flint said a 46% drop in the wholesale price which was not passed onto customers when her party were in charge, but warned bills were getting worse under the coalition government.
"Prices are going up three times as fast under this Government than they were under us and we need to tackle that."
Environment Secretary Owen Paterson has told water firms it is "crucial" that water bills are kept affordable for "hardworking people".
We know that 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, introduce social tariffs for vulnerable customers and crack down on bad debt.
Environment Secretary Owen Paterson has called on water companies to "look closely" at whether price increases are necessary and introduce special tariffs for hard-pressed households.
In a letter to suppliers, Mr Paterson said the firms should recognise the financial strain people are under.
The intervention came ahead of an Ofwat ruling expected later this week on an application from Thames Water to increase bills by £29 in 2014-15.
The regulator is expected to reject the application and has questioned the profits being made by firms.
It suggested its next Price Review could ease the upward pressure on bills by up to £750 million after 2015.
David Cameron has never shown any interest in rising water bills and has wasted three years doing absolutely nothing to address the impact on already over-burdened family budgets
The Department for Environment, Food and Rural Affairs has confirmed the government's move to examine water prices next week.
The Government is working across the board to reduce the cost of living and help hard-working households who are feeling the pinch.
We want to ensure customers get a good deal from the water sector and will be setting out our approach next week.
Prime Minister David Cameron will take action to help households struggling to meet rising water bills, his spokesman said.
"There'll be some progress next week on water bills," the spokesman said. "The prime minister wants to see household expenditure being brought down."
His comments suggested that Britain's biggest water companies could join energy giants at the centre of a political row over the rising cost of living ahead of an election in 2015.
Millions of families in Britain could face higher bills under new government plans to install compulsory water meters in homes, the Daily Telegraph has claimed.
The Environment Secretary, Owen Paterson MP, this week approved plans to make water companies across a third of the UK fit meters and bill customers for usage.
Ministers have warned that reservoirs are at risk of running dry due to water shortages.
A study of 86,000 British homes by the Energy Saving Trust Foundation found the following:
- Hot water use contributes £228 to the average annual combined energy bill
- Britons shower 4.4 times a week and take 1.3 baths on average
- The average shower lasts 7.5 minutes. Cutting a minute off that time could save households £215 million each year.
- Just over a fifth of household water is used by kitchen appliances such as dishwashers, kettles, taps and washing machines
- 95% of people boil the kettle every day while 75% of people overfill
(Energy Saving Trust Foundation)
Three-quarters of British households are wasting £68 million a year by overfilling the kettle, according to a new report.
The study by the Energy Saving Trust Foundation found that many small changes to the way we use water could result in big savings on energy bills.
Some of the areas where the biggest savings could be made are by reducing time spent in the shower and by using a modern dishwasher rather than washing by hand.