According to a new league table published by Ofgem, Utility Warehouse and Scottish and Southern Electricity (SSE) have the highest proportion of customers stuck on a standard variable tariff, with 94% of Utility Warehouse customers and 91% of SSE customers on a standard variable tariff. British Gas and E.On were next in line with 74% and 73% respectively, followed by Npower at 59% and EDF Energy at 56%.

The energy suppliers with the smallest proportion of customers on a standard tariff were Extra Energy with 14%, and and First Utility with 9%.