Energy bills will fall by 7% in July - the first drop for a year, energy regulator Ofgem has announced.
It means a household using a typical amount of gas and electricity will see their annual bill fall by £129.
The regulator's price cap, which is set every three months, sets a maximum that suppliers can charge for each unit of energy, affecting 21 million households in England, Scotland and Wales.
Tim Jarvis, director general of markets at Ofgem, said the drop in energy bills reflected a fall in the international price of wholesale gas.
"However, we're acutely aware that prices remain high, and some continue to struggle with the cost of energy," he added.
The fall comes at the warmest time of the year, when energy use is lower, but analysts expect little change in prices in October."
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