Energy suppliers have been given three weeks to justify harsh increases in direct debit payments as households battle a cost of living crisis.
An investigation will look into claims they are ripping off customers by inflating direct debits by more than the price cap to ease cashflow problems.
Kwasi Kwarteng, the business secretary, said companies had three weeks to respond to allegations of "completely unacceptable behaviour" relating to unjustified direct debit increases.
