Ms Fahnbulleh said: “It is vital that consumers who are experiencing debt – or who are at risk of falling into debt – are given the support they need by their suppliers.”
EDF, which has 5.2m domestic and business customers in the UK, said 469,000 customers owed a total of £518m. The average debt per customer has also risen from £757 two years ago to £1,104 today.
Philippe Commaret, UK managing director of customers at EDF, said: “Our reliance on globally traded fossil fuels means that prices have unfortunately increased significantly over the past few years.
“We have continued offering assistance to those in need … but with costs rising, customers need urgent assistance in both the short and long term.”
Customer debt at British Gas owner Centrica, whose 7.5m residential customers make it the UK’s largest supplier, surged from £501m in 2022 to £764m in 2023. A spokesman said: “We’re supporting those who need help the most.”
Eon, whose 5.6m customers make it one of the biggest UK suppliers, said there were limited options given global prices and UK regulation.
A spokesman said: “There is only so much energy suppliers alone can do to address the issue of energy affordability and bring down energy bills.”
Eon has called for wholesale reform of the UK energy market, including the introduction of social tariffs where the poorest households are effectively subsidised.
Mr Kelty, of Panmure Liberum, predicted a continuing surge in energy debts whatever threats the Government made against suppliers.
He said: “We are currently in the low demand summer season and there is little chance that prices will fall over the winter, so all risks to gas prices lie to the upside.”
He said it was unfair for politicians to push the blame for rising prices and debts on to suppliers.
“Given that political decisions are causing stress on household finances, it should be shared by both parties.”