Figures published this week reveal nearly 1.8 million gas and electricity accounts were in the red in the three months to June, up 12% on the previous quarter.
And the data, released by Ofgem, is just the tip of the iceberg. It only measures those customers who have come to an arrangement with their supplier to clear their arrears over time – and does not include many others who are behind with their bill but suffering in silence.
Even more worrying is the fact that, since the data was compiled, millions have been hit with energy price hikes of up to 20%. The rise, the second in less than a year, has left the average customer facing a bill of more than £1,300 a year to heat and light their home.
The report shows more than 926,300 with a standard or pre-payment electricity meter were repaying an average debt of £318 between April and June. Around 854,000 gas customers were also officially classed as in the red, owing an average of £316.
In many cases, households will have run up debts for both gas and electricity.
Particularly alarming is the number falling behind and struggling with other bills. About 139,000 electricity and 119,000 gas customers owe more than £600.
An Ofgem spokesman said: “We are concerned by the increasing number of customers with large debts, particularly in gas. The recession and high energy bills are continuing to have a significant impact.”