The number of customers switching gas and electricity suppliers each month has plummeted since last September, according to Ofgem.
The energy regulator says the number of people changing electricity suppliers fell by 62.5 per cent, and those switching gas suppliers dropped by 40 per cent, in the past four months.
Between May 1998 and last September, 320,000 consumers a month switched electricity suppliers. The figure has since dropped to 200,000.
In the same period, 200,000 gas customers switched suppliers each month, but the total has now fallen to 80,000 a month.
This is despite Ofgem claims that customers that switch their gas supplier can save up to one-fifth on some bills, with direct debit customers saving up to 14 per cent.
John Evans, marketing director of PowerGen, adds: “The slowdown is because some smaller companies may not be signing up people at the same rate as others.”
According to a National Audit Office report titled “Giving Domestic Customers a Choice of Electricity Supplier”, electricity customers could reduce their bills by a total of &£700m a year, or 13 per cent, if they switched supplier.