Robin Hood Energy is among dozens of small energy suppliers that have been launched to take on the Big Six. A missed deadline to pay £9.4 million will raise fears over the financial health of the supplier

The energy regulator has threatened to close down Britain’s first council-run gas and electricity supplier after it failed to pay millions of pounds it owes under a green power scheme.

Robin Hood Energy, owned by Nottingham city council, missed a September 1 deadline to pay £9.4 million it owed under the Renewables Obligation scheme, which supports wind and solar projects. The missed payment will raise fears over the financial health of the supplier, given that at least a third of suppliers that failed to meet the deadline last year have gone bust or ceased trading.

Robin Hood Energy said that it was waiting for a suitable “letter of comfort” from the council to say that it would continue to support the company financially over the