There are fears of gas shortages in Ukraine after Russia announced it would raise its prices. But will that affect the rest of Europe?
Believe you may be among the 3.5 million households or 300,000 businesses owed part of £400m from the Big Six? Here's how to claim it back.
There's been a worrying increase in the number of children who live in homes hit by fuel poverty, according to new figures.
Ofgem will today call on the Big Six energy companies to hand back more than £400m that remains in accounts closed by their former customers.
Around 3.5 million households and 300,000 business accounts are believe to be affected by the issue.
The Big Six - Centrica's British Gas, EDF Energy, Eon, Npower, Scottish Power and SSE - supply 98% of UK homes and have all increased their prices in recent months.
Ofgem chief executive Andrew Wright is understood to have written to the companies telling them to give customers whose accounts were not shut down properly their money back.
He wants any funds that cannot be returned to be used to reduce bills for existing customers.
Research has analysed the efficiency of domestic fridges, testing the energy label declarations over a two-year period between 2009 and 2011.
Philip Sellwood, chief executive at the Energy Saving Trust, a social enterprise group with a charitable foundation, called for more to be done to address the findings of the project.
– Philip Sellwood, chief executive at the Energy Saving Trust
We need to address the fact that consumers across Europe are not maximising the energy saving benefits stated by millions of products.
There is an obvious need to recoup any potential savings through establishing more rigorous market surveillance and standards across energy efficient products and labelling.
The European Commission has recognised that this energy wastage is a problem, and is keen to ensure a compelling climate of compliance across all aspects of energy efficiency.
The Energy Savings Trust will tackle the problem with mystery shoppers, who will test products in an attempt to prevent misleading energy claims.
MarketWatch, as the scheme will be known, will be a three-year programme with more than 300 inspections in shops and 300 in online stores.
Consumers are being misled after research found one in five household products do not match their energy-efficiency claims, according to the Energy Standards Trust.
European Commission-funded research found that up to 20% of products - including ovens, fridges, washing machines and dishwashers - did not comply with energy-efficiency standards.
As a result, 10% of potential energy savings promised are missed by millions of products across Europe, the Trust said.
The MD of British Gas has issued a fresh statement in response to Energy Secretary Ed Davey's letter to Ofgem in which the Cabinet minister called on the regulator to probe 'Big Six' gas profits as part of an investigation across the industry.
Chris Weston said its parent company Centrica "does more than any other organisation to secure gas and power for British customers, with commitments totalling more than £60 billion, and we can only shoulder responsibilities on this scale if we are a profitable business". He added:
In the last six years we have invested £13.7 billion, which is equivalent to £1.85 for every £1 earned. We also support jobs and growth in Britain, directly employing more than 30,000 people. Our annual tax bill is around £1 billion, making us one of Britain’s biggest corporate tax-payers.
The current assessment of the energy market will be essential to rebuilding trust in the sector. We strongly support a proper, thorough and independent examination of the issues during this process.
Energy Secretary Ed Davey has been accused by a leading trade union official of sparking a "witch hunt" against energy firms and threatening jobs by pursuing a vast investigation into the 'Big Six' energy companies and their profits.
Gary Smith, the national officer of the GMB union, was angered that British Gas, in particular, had been singled out by the Cabinet Minister in his letter to the energy watchdog Ofgem. Mr Smith said:
British Gas is probably the biggest employer of apprentices and trainees in the UK. Hundreds of apprenticeships in smart metering that would have been created this year probably won't be because of Davey's dithering over policy.
He now threatens to wreck thousands of more jobs. If an investigation is warranted it should have been carried out appropriately not by a ministerial leak to the press leading to a witch hunt.
Mr Davey's intervention was welcomed, though, by the Federation of Small Businesses, whose national chairman, John Allan, said:
Over 40% of all small businesses are with British Gas and it simply cannot be right that one company has such a dominant share, especially given the price of gas now accounts for between five to 10 per cent of total business costs for nearly one in 10 of the UK's smallest businesses.
The business energy market is in desperate need of reform and we want to see radical measures put in place to increase transparency in the market and allow small firms to switch to more competitive energy deals with ease.
British Gas has said it will "participate fully" in discussions about gas profits after being singled out by the Energy Secretary in his call to the industry watchdog to examine the 'Big Six' energy companies.
Ed Davey said in a letter to the head of Ofgem that British Gas had tended "to charge one of the highest prices over the past three years, and has been on average the most profitable".
British Gas issued the following statement in response:
There is an ongoing independent market assessment being conducted by the OFT (the Office of Fair Trading), Ofgem and the Competition & Markets Authority.
We welcome this and have complied with all the requests for data which we have received.
Further discussions have been arranged over the coming weeks in which we will fully participate.
– British Gas
The data referred to in the Secretary of State's letter has already been fully disclosed and in the public domain for a number of months.
We share the Secretary of State's wishes to see greater interconnection between the UK and other European energy markets and we also wish to see European markets open up to full retail competition.
British Gas has also fully embraced the Green Deal which is already beginning to have a positive impact in reducing consumer bills.
Energy secretary Ed Davey has pointed to the "lack of transparency" in the accounts of the "Big Six" energy firms as to why he has urged the industry regulator to investigate their profits.
Shadow energy and climate change minister Jonathan Reynolds accused Ed Davey of spending months defending energy firms despite evidence of overcharging.
– Shadow energy and climate change minister Jonathan Reynolds
Actions speak louder than words - and this Government has let the energy companies get away with increasing their profits on the back of spiralling bills for hard-pressed consumers.
If the Government wants to be taken seriously on energy bills, nothing less than a price freeze and action to stop these firms from overcharging in the future, as Labour has proposed, will do.
Energy Secretary Ed Davey has urged Ofgem to look at the profits made in gas by the 'Big Six' energy companies:
– An extract from Ed Davey's letter to Ofgem
Clearly you will wish to consider whether this is prima facie evidence of an issue in the market and so whether it merits a market investigation reference with the whole gamut of potential remedies that could follow including a break up of any companies found to have monopoly power to the detriment of the consumer.
Alternatively you may of course conclude that no action is needed or potentially some intermediate measure which can be taken by the sector regulator.
Mr Davey's letter also suggests looking at whether the Big Six should adopt a different business model and how well British energy markets are linked to those in mainland Europe.
Ofgem said it would look at all evidence while compiling its report with the CMA and OFT. It declined to comment further.
Energy Secretary Ed Davey has urged the energy regulator to look into the profits being made by the 'Big Six' energy companies made through supplying gas.
The Liberal Democrat urged Ofgem to examine whether their profit margins - in some cases five times higher for gas than for supplying household electricity - should be the subject of an investigation.
If such an investigation was to find evidence of a monopoly, it could result in a company being broken up.
Davey claimed gas made up two-thirds of the energy bills of households connected to the grid and that if profit margins for gas came down to a similar level to those in the electricity market it could save every household £40 per year.
The recommendation came in a letter to Ofgem chief executive Andrew Wright, in which Mr Davey singled out British Gas.
He said there was evidence the company, which has the greatest share of the domestic gas market, had tended "to charge one of the highest prices over the past three years, and has been on average the most profitable".