Energy firms are facing increased pressure from the Government to pass on a fall in wholesale costs to consumers by slashing household bills .
Amber Rudd, the Energy and Climate Change Secretary, has written to the Big Six energy companies asking them to alter their prices now a pre-election pledge by Labour to impose a freeze was off the table.
The latest analysis by regulator Ofgem found firms could increase their profit margins to up to £118 on an estimated annual dual fuel deal this year, while wholesale gas and electricity costs were £80 lower than they were estimated at a year ago.
Ms Rudd told the Daily Mail: " Labour's price freeze was a theme for why they were unable to reduce prices before the election.
"Now that threat is no longer there, I intend to keep up the pressure on them to act."
She added: " My focus is to get the best deal for consumers and the department is working hard to keep energy bills as low as possible.
"That is why I have written to energy companies asking them what their plans are to lower bills for hard-working British bill payers."
A spokesman for Energy UK told the paper: " Our members will be replying to the Secretary of State in due course and the industry as a whole is keen to work constructively with the new Government to ensure energy security at a price everyone can afford."
Prior to the general election, then Labour leader Ed Miliband promised a price freeze and new powers for Ofgem to enforce reductions.
But the measure was criticised by Conservatives, who said it provided a barrier to cuts.
Last week SSE, the UK's second biggest supplier, reported a 39% increase in profits to £456.8 million for the year to March 31, meaning that it made an average of £69 from the supply of household electricity and gas - before tax and interest payments.
But it also revealed it had lost more than 500,000 customer accounts in the last year, despite its pledge to freeze bills until at least July 2016, citing "increasingly challenging and highly competitive market conditions".
The Competition and Markets Authority is currently undertaking a wide-ranging probe into the energy market to see if customers are being unfairly treated by the UK's dominant big six energy suppliers.