Britain's energy giants received more than 5.5 million complaints last year, consumer group Which? revealed yesterday.

Which? said the Office of Fair Trading and energy watchdog Ofgem should refer the market to the Competition and Markets Authority for investigation.

But the Fuel Poverty Action Group called for profit-driven energy companies to be replaced with “publicly owned and community-controlled” suppliers.

Complaints ranged from issues with bills and metering to customer service, switching and payments.

Of the 5,579,665 complaints in 2013, Npower received 1,383,650 — the most of all the big six companies.

EDF followed with 1,240,005, British Gas with 1,235,550 and Eon with 929,230.

The watchdog’s latest figures show that eight in 10 consumers are worried about rising energy prices and just one in five trust gas and electricity suppliers.

Which? executive director Richard Lloyd said: “Millions of people are unhappy with the service they receive from the suppliers.

“Next month, we want the regulators to refer the energy market to the Competition and Markets Authority and launch a full scale inquiry.”

Fuel Poverty Action Group spokeswoman Eva Joy agreed that public trust is at an all-time low but said an inquiry was not the answer.

She told the Star: “It’s useful to point out how hated they energy companies are. However the problem is the market itself. It should be abolished and be replaced with not-for-profit, publicly owned and community-controlled energy suppliers.”