Research by the Organisation for Economic Cooperation and Development has found that bills for power and food in the UK have risen at twice the rate than in other European Union member states.
Mr Haddelsey said that as wholesale energy costs "have tumbled recently", energy firms "ought to start passing reductions" to consumers.
He stated: "Wholesale prices are the lowest for 12 months or more, and that is already having an impact for industrial and commercial energy customers
"It will take longer to filter through to domestic customers."
Paul Golby, chief executive of E.ON, recently hinted that its customers could see price drops "next year" in gas electricity prices.
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