First Utility raises energy bills by 18pc This new tariff, however, comes with a promise to check its own prices each week against the standard tariffs of the big six - British Gas, EDF, E-ON, Npower, Scottish Power, SSE - and ensure it is lower. Ian McCaig, chief executive, told customers: "The energy industry as a whole is under pressure from increasing costs. These include charges for delivering electricity and gas to your home, mandatory government environmental schemes and social obligations, as well as the price we have to pay for energy on the wholesale markets. Although First Utility has been subject to the same challenging cost increases as other energy suppliers, I chose to delay changing our prices for as long as possible and until customers were through the coldest winter months. The big six all announced price rises by the end of 2012 during a period when heating your home costs you the most. Other small suppliers - Ovo Energy and Co-op Energy - have also recently increased prices. While First Utility's new price promise will undercut the standard tariffs, households will still be able to save by switching to one of the latest special offer tariffs on the market. The process of switching is fairly simple but the pricing structures can be confusing. Ofgem, under pressure from the Government, is trying to make it easier for customers to get the best deal. But Which?, the consumer group, has warned that the reforms could leave the market more complicated rather than less. Ofgem's consultation on the proposals closed yesterday. First Utility and Npower were involved in a spate earlier this month when the larger company said smaller energy suppliers had an advantage. Npower had attacked policies exempting small suppliers from schemes to promote energy efficiency and help vulnerable customers, which cost about £97 per household per year. But in a letter to The Daily Telegraph, First Utility's Mr McCaig said his company was now obliged to take part after passing a minimum customer threshold last year of 250,000 customer 'connections', or 125,000 dual-fuel customer accounts. He said the company was happy to take part but that under one of the schemes, the Energy Company Obligation, First Utility actually had to pay double the costs a Big Six supplier would have to pay for each new customer it acquired. He accused the big six of using "artificially low tariffs to attract new customers at a loss in order to quash competition" and claimed they subsidised this by making millions of customers pay "over the odds on their standard tariffs." iSave v12 (existing tariff) iSave Everyday (new tariff) Electricity standing charge (p per day) Electricity unit rate (p per KWh) Gas standing charge (p per day) Gas unit rate (p per KWh) Which are the cheapest deals? The current cheapest online discounted variable tariff, according to Energyhelpline, is SSE's Discounted Energy Bonus October 2014. It says the cheapest fixed tariff is Npower's Online Price Fix June 2014. >> READ THE FULL REPORT ON THE CHEAPEST DEALS