Shameless energy privateers will slap inflation-busting bills on families in fuel poverty for the next 17 years, Parliament's energy watchdog warned yesterday.

The National Audit Office (NAO) said companies will squeeze households to recoup the cost of investment in ageing energy infrastructure.

Government ministers want two-thirds of funding for a £310 billion renewal programme to come from privateers.

They admit energy costs will soar by at least 18 per cent by 2030 as a result, while one water companies predicted its bills will rise by 28 per cent.

But NAO head Amyas Morse said the Con-Dems have no idea what effect that will have on Britain's poorest families.

He said: "Government and regulators do not know the overall impact of planned infrastructure on future consumer utility bills or whether households, especially those on low incomes, will be able to afford to pay them."

The Department for Energy and Climate Channge estimates that 11 per cent of households are now in fuel poverty.

Electricity, gas and water bills already strip low-income households of 15 per cent of their annual budget - compared with 11 per cent in 2011.

But that hasn't stopped Energy UK, which represents Britain's big six, suggesting yesterday that it would double its bills over the next six years.

Labour MP Ian Lavery roasted the bosses over their greed when they appeared in front of Parliament's the energy select committee last month.

And he told the Star the latest warnings are further evidence that the whole system is broken.

He said: "It's been suggested that it's going to be the coldest winter we've had for many years and if that's the case then how many people are to lose their lives because they cannot afford electricity.

"That should not be the case.

"We should look at all possibilities of future ownership of the energy supply companies and that includes some form of national interest company, which is controlled by the state.

"The simple adage is, if you don't own it, you can't control it."

Mr Lavery's call was supported by the Fuel Poverty Action Group (FPAG), which announced a day of direct action to "bring down the big six."

UK Uncut, Disabled People Against Cuts and Greater London Pensioners Association will join the protest on November 26.

Hundreds of activists will descend on the London headquarters of one of the big six and target British Gas's new Oxford base.

FPAG spokeswoman Clare Welton said: "These stark warnings show that if we continue to leave our energy and basic utilities in the hands of profiteering private companies, the squeeze on millions of hard-up households and the fuel poverty crisis will only worsen."