Customers will be able to switch more quickly between electricity and gas companies under a deal to be announced within days.
The “big six” energy firms have agreed to halve the average delay of five weeks faced by households who want to cut their bills by changing supplier.
The plan will be confirmed this week by Ed Davey, the Energy and Climate Change Secretary. He will also announce moves to make it easier for people to go back to their previous supplier if they are unhappy with their new deal.
Customers could cut their power bills by as much as one-fifth if they regularly move between suppliers, analysts believe.
The “big six” - Centrica, SSE, RWE Npower, E.On, EDF Energy and Scottish Power - account for about 95 per cent of Britain’s energy market. They face an investigation to check whether they are preventing effective competition.