UK households have been issued a £700 energy bill warning ahead of price hikes in October.

Last week, industry regulator Ofgem confirmed an 80.06 per cent rise, or £1,571, with the new cap coming into effect for around 24 million household in England, Scotland and Wales next month.

Ofgem’s chief executive Jonathan Brearley warned of the hardship energy prices will cause this winter and urged the incoming Prime Minister and new Cabinet “to provide an additional and urgent response to continued surging energy prices”.

Now new research has found families with inefficient homes will be paying more than £700 a year extra in energy bills from October than more efficient properties.

Households in England and Wales living in the 19 million homes rated with an energy performance certificate (EPC) of D or below face an average bill increase of £1,730 per year.

This compares to an increase of £982 per year for those in the third of housing which meets the government’s target energy efficiency rating of C or above – leaving a staggering gap of £748, according to research by economics consultancy Cebr.

Typically houses with double glazing, good insulation, energy-efficient boilers and LED lighting receive a better EPC, with an A rating the best and G the worst.

How to reduce your energy bills

Boris Johnson defends legacy amid cost of living crisis

Boris Johnson has said the UK is one of the most successful countries on earth and has the financial strength to get through the cost-of-living crisis.

Th outgoing Prime Minister said investments were making the UK “fit for the future” and the country would get through the current “pressures” on living standards.

Asked whether Britain was “broken” in the final days of his leadership, he responded: “Absolutely not. This country has got an incredible future and has everything going for it.