More than one in 10 households are struggling with energy costs in England, with 2.28 million homes in fuel poverty in 2012, official figures show.
The number of fuel poor families fell by almost 5% in 2012, the latest year for which figures are available, from 2.39 million homes in 2011 - but it is expected to rise again by 2014 to 2.33 million, largely due to increases in energy costs .
The gap between the bills fuel poor households face and what they can afford to pay was £443 on average in 2012, the latest year for which figures are available, but is expected to increase to £480 on average by 2014.
The latest figures from the Department of Energy and Climate Change prompted renewed calls for action to improve energy efficiency and bring down bills.
They come as the Big Six energy companies have been urged to explain to customers what impact falling wholesale energy prices will have on bills, with gas prices for next day delivery reaching their lowest level since September 2010 in early June.
The Government has changed the measure for fuel poverty to take into account households with both high energy bills and low incomes.
Under the old measure, which included everybody who had to spend more than 10% of their income to heat their homes properly, some 3.05 million English households were in fuel poverty in 2012, down on the 3.2 million homes in fuel poverty in 2011.
The Government has faced criticism for ''shifting the goalposts'' to bring down the number of households classed as in fuel poverty.
The report from Decc said the fall in the number of households in fuel poverty in 2012 was mainly due to increasing incomes for higher income fuel poor families.
Those living in private rented accommodation continued to have the highest rates of fuel poverty.
Across England, 10.4% of homes were classed as fuel poor, while regionally the West Midlands had the highest levels of people struggling with bills, at 15%.
The lowest was the South East with 8%.
Energy and climate change minister Greg Barker said: "I am encouraged by this further modest fall in the number of households living in fuel poverty.
"This welcome progress shows that while we can't control volatile energy prices we can continue to improve the energy efficiency of our housing stock.
"The Coalition Government is doing everything it can to help hard-pressed families keep their energy bills down."
He said energy efficiency programmes - the energy company obligation and the green deal - had supported more than 372,000 low income and vulnerable households.
And he said the warm home discount provided 1.2 million of the lowest income pensioners with £135 of their electricity bills, while efforts to reduce bills by £50 on average would also help.
Shadow energy secretary Caroline Flint said: " Fuel poverty is rising and the gap between people's bills and what they can afford growing too, yet David Cameron is doing nothing to stand up to the energy companies or reform the energy market.
"To help people with their energy bills, the next Labour Government will undertake the biggest overhaul of our energy market since privatisation.
"Our plans will break up the big energy companies, put an end to their secret deals and create a tough new regulator with the power to force companies to cut their prices when wholesale costs fall.
"And until these reforms kick in, we will put a stop to unfair price rises by freezing energy bills until 2017, saving the average household £120."
Sophie Neuburg, Friends of the Earth fuel poverty campaigner, said: 'While the slight fall in fuel poverty is encouraging, it's completely unacceptable that millions of people across Britain are still struggling to pay their bills.
"These figures also show that those on the lowest incomes are being hit even harder.
"With more fuel price hikes expected in future, a comprehensive, publicly-funded energy efficiency programme to insulate every low-income home in the country is urgently required.
"Slashing energy waste would not only save households hundreds of pounds every year, it would also create jobs, tackle climate change and reduce our reliance on overseas fossil fuels."
Caroline Abrahams, charity director for Age UK, said: "Unfortunately, today's statistics show that fuel poverty is still a huge problem.
"As an older people's charity we are particularly worried about the plight of nearly a million pensioners who can't afford to heat their homes properly, but they aren't alone - fuel poverty impacts on other households too, including families with children.
"In the long-term, the only sensible solution to fuel poverty is an ambitious energy efficiency programme to bring all our housing up to standard."