Energy firms installing prepayment meters will be required to try to contact a customer at least ten times and conduct a "site welfare visit" before forcibly conducting the installation, new guidelines will say.

Energy company workers will also be required to wear body cameras or sound recorders to make sure new energy regulator rules that govern prepayment meter installations are being adhered to.

Ofgem's new code of practice for prepayment meters will outright ban forcibly installing prepayment meters in the homes of people with a terminal illness and those aged 85 and older who don't have someone to care for them.

People with a health condition that would be worsened by living in a cold home - such as emphysema and sickle cell disease - will also be protected from forced installation, as will people who require a continuous supply of electricity for medical equipment.

Under existing rules, meters are not to be installed in the homes of vulnerable customers. But an investigation by The Times newspaper found debt collectors working for British Gas had forced their way into the homes of vulnerable customers.

The head of British Gas parent company Centrica apologised on Sky News after the report came to light.

The rules around prepayment meters have been revised in consultation with government, stakeholders and industry after the scandal emerged.

In February Ofgem asked suppliers to temporarily suspend the practice of forced installation and review their processes for dealing with customers who have fallen into arrears.

Prepayment meters are pay-as-you-go devices that require top-up payments to provide gas and electricity to a home. Energy providers install the meters to customers who are in debt to avoid them amassing higher bills.

If payments are not made, no power is supplied. In an effort to prevent households being immediately without power, £30 credit will be given under the new rules.

The top-up payments are more expensive than paying bills, something Chancellor Jeremy Hunt said would end in July.

Official figures showed more than 94,000 meters were installed in homes in Britain throughout 2022.

Ofgem will announce full details of the code of practice, which firms have agreed to be bound by, on Tuesday morning.

But the new guidelines, originally reported in The Guardian newspaper, have fallen short of some groups' expectations.

Disability equality charity Scope, said: "This process will still allow energy companies to install prepayment meters in some disabled households".

"We want to see the forced installation of meters and remote switching banned outright for disabled people," Tom Marsland, Scope policy manager said.