‘People should not be put off switching’

not insolvent ‘ where possible’. But a spokesman says it ‘closely monitors suppliers’ conduct and any potential risks to consumers’.

Malinowski says: ‘The hurdles for setting up as an energy supplier are low.

‘Companies that already have a licence ready to go can simply be bought off the shelf.’

An example of this is ‘Supplier in a Box’ operated by Utiligroup – offering a new entrant everything it needs to get up and running.

It was behind Co- operative Energy which has flourished as a mid-tier provider.

Another customer was Tempus Energy, which closed its UK energy supply business following the Brexit vote in 2016. The company asked Ofgem to revoke its electricity supply licence and all of its customers switched elsewhere.

CUSTOMER SERVICE PROBLEMS

HOUSEHOLDERS comparing tariffs should be careful not to pick a deal on price alone.

Malinowski says: ‘It is a minefield out there. If you have not heard of a company you have to do your research.

‘Check the terms and conditions for payment and read customer and energy expert reviews.’

Though bigger energy providers field the highest proportion of complaints, when a small supplier hits a bump in the road often it does not have the resources to deal with problems swiftly. For example, Nottingham-based gas and electricity supplier Iresa, which is being investigated by Ofgem over its treatment of customers, has struggled with large volumes of calls.

When The Mail on Sunday tried calling the company last week, it was 110th in the queue.

Despite the broad spectrum of customer experiences across the market, switching is still the easiest way to save significant sums of money on bills.

Earl adds: ‘People should not be put off switching for two good reasons.

‘First, it is the best means of saving hundreds of pounds a year on your energy bill.

‘ Secondly, if a company collapses, Ofgem will transfer your contract to a new provider and at no time should you lose power.’