supplier

However a period of high prices - which analysts say is likely to continue - means households have collectively built up debt of £3.7bn to suppliers.

That is a very big “if”, but it is weighing on the minds of energy suppliers.

Some £3.7bn is collectively owed to energy suppliers from people unable to pay their gas and electricity bills, for example.

E.On failed to pay the credit in the accounts of mostly vulnerable customers who had ended their contract with the supplier in a mandatory six-week window.

Posing as a business wanting to import knives into Western Europe, the BBC asked the supplier for its latest product list, costs and a shipping estimate for 30,000 knives.