Consumer group Which? Has launched a campaign called The Big Switch, urging people to sign up to a big group which energy providers would then compete to provide gas and electricity to at the most competitive possible price in a reverse auction.

Which? has teamed up with the online campaigning group 38 Degrees to launch The Big Switch, and is asking consumers to sign up by March 31st.

Executive director Richard Lloyd said: “Thousands of people tell us that they want a much better, affordable energy deal. It’s a £4 billion free kick for the energy companies if so many of us stick with their more expensive tariffs.

“The Government, regulator and energy companies have failed to move quickly enough to improve things for consumers when so many are struggling to pay their bills. That’s why we decided to launch The Big Switch. This is a completely new way to buy energy as a group. The bigger the group, the stronger our bargaining power will be.

“We are urging anyone who is angry about the state of the energy market to sign up.”

The Big Switch will be run on one day as a reverse auction, which involves energy companies submitting their lowest price per kilowatt of electricity and cubic meter of gas.

Which? said that once a deal is done , group members will be notified by either email or text message and they can then choose whether or not to accept it. There will be no commitment or obligation to sign up with the new supplier. Which will handle the swicth for those who do wish to change provider.

David Babbs, executive director of 38 Degrees, said:

“We’re all sick of gas and electricity companies ripping us off. If thousands of customers band together, we’ll have the bargaining power to do something about it.”