Complaints about EDF Energy have risen by nearly 20 per cent, while the rest of the Big Six suppliers have seen a fall in the number of grievances, according to a watchdog's latest findings.
Consumer Focus said there had been an overall fall in the number of complaints made about the major energy suppliers in the spring quarter, with the fewest seen in April.
SSE remained on top with the smallest number of complaints, while EDF fell to fifth place after seeing its complaints increase by 19 per cent. The performance has been attributed to its introduction of a new billing system.
Meanwhile British Gas, E.ON and Scottish Power all saw a decline in complaints, as did npower, which moved up to fourth place in the league tables after EDF's poor performance.