Figures on companies' profit margins have prompted claims and counterclaims

Consumer groups are calling for long-term commitments from the energy industry at a summit on gas and electricity prices at Westminster.

The meeting of industry bodies and others on Monday has been called by Energy Secretary Chris Huhne.

Last month, Mr Huhne said he planned to "get tough" with the major energy firms on gas and electricity tariffs.

Regulator Ofgem has just revealed a rise in firms' profit margins - figures challenged by the industry.

Ofgem also announced plans to simplify tariffs in order to allow customers to compare prices more easily.

The cost of gas and electricity has risen by up to 18% in the past few weeks, with the cheapest dual-fuel deals - for those with online deals - having broken the £1,000 barrier for the first time.

This prompted the Department of Energy to call the summit to examine ways in which customers can take action to save money.

But the consumers' association Which? said the meeting should look at more fundamental factors affecting the market.

"This summit has to address longer-term issues too, like being clearer about what is driving price increases and identifying ways for energy companies to start rebuilding trust with consumers," said executive director Richard Lloyd.

"We need commitments from suppliers and the government to put an end to practices that harm consumers and action to create a competitive energy market that works for everyone."

Mike O'Connor, chief executive of watchdog Consumer Focus, said: "With winter round the corner, millions of people across the country will be worried about their energy bills.

"Many of the most vulnerable households will be facing difficult decisions about whether to heat their homes or cut back on other essentials.

"Government, energy firms and consumer organisations have a responsibility to make sure that consumers get all the help they need to cut their bills. We are committed to doing what we can to make sure consumers can keep warm and control their costs."

On Friday, Ofgem said that the profit margin for energy firms had risen to £125 per customer per year, from £15 in June.

But the industry said that the snapshot of profits did not provide a realistic picture of the average profits over a year.

The regulator also published its simplification plan, which said suppliers would be forced to have no-frills tariffs, which would consist of a standing charge - fixed by the regulator - plus a unit charge for energy used.

It means that the only number consumers would have to compare between suppliers would be the unit energy charge.

Ofgem will publish its detailed proposals for consultation next month and hopes to have implemented some of its reforms in time for winter 2012.