According to comparison site uSwitch.com, the Co-operative Fixed March 2015 tariff is now the cheapest fixed price plan on the market costing consumers £1,168 a year, making it £224 a year cheaper than the average ‘Big 6’ standard plan.

The new fixed-price plan now knocks fellow small supplier, Ovo Energy, off the top spot, after it spent a week in the spotlight with its New Energy + Ovo Just Reward plan at £1,175 a year.

Co-operative Energy’s deal is £7 a year cheaper and is fixed for four months longer, without an exit penalty.

In contrast, with Ovo’s plan customers will have to pay £30 per fuel if they switch before the fixed period is over.

Tom Lyon, energy expert at uSwitch.com, said: “To see another small supplier at the top of the ‘best buy’ table is fantastic news and a welcome indication of what real competition could achieve in this market. The deals are there and it’s in the hands of consumers to snap them up and fan the flames of competition. Only with a healthy competitive market will we see suppliers battle it out to offer the cheapest plans, superior services and to drive costs and inefficiencies down.” 

The third cheapest fixed price tariff comes from a small supplier too, First Utility. Its tariff costs £1,178 a year matching the cheapest big six tariff on the market, E.ON’s Energy Fixed 1 Year.

Meanwhile, another small supplier, Spark Energy continues to reign as the cheapest overall supplier with its Advance 2 tariff, costing £1,116 a year – £52 a year cheaper than Co-operative Energy’s deal.

However, consumers should note that this is a variable plan and so it won’t protect from price rises. It also requires payment in advance, which may not be suitable for everyone.

Lyon added: “In recent weeks, we have seen the number of consumers switching to smaller suppliers soar from 17% to 29%. This is encouraging, but many are still reluctant to take the leap. The good news is that their fears are unfounded and, with the right education and support, consumers could have the confidence to try out a new supplier and benefit from one of these competitive new deals.”