The cost of an average family’s annual energy bill could reach nearly £5,300 from April if current sky-high wholesale prices for gas and electricity do not fall soon.
In a new forecast, models designed by experts at energy consultancy Auxilione predicted that the price cap on energy bills could reach £3,628 in October, from £1,971 today.
It could then rise again to £4,538 in January and peak at £5,277 in April.
This is the worst forecast yet for the millions of households set to face crippling bills this winter.
It is also the latest in a series of progressively worsening forecasts. The predictions are becoming more dire because the price of gas and electricity on wholesale markets keeps going up.
The April forecast, which was made on Friday morning, is £240 more expensive than the previous prediction for the same month, made just 24 hours earlier.
However, if energy prices start falling then the predictions will fall.
The figure given for the price cap is based on what an average household uses. Those who use more than average will have to pay more, and those with less usage will face smaller bills.
The cap is based on the price that suppliers pay to buy energy which they then sell on to households. This is known as the wholesale energy price.
Energy regulator Ofgem observes this price over the months leading up to when it has to change the price cap. It calls this the observation window.
The cap is changed four times a year – in October, January, April and July.
Most of the observation window for October’s price cap has now passed, so forecasters are very confident that their predictions will not be far off when Ofgem announces the cap level on August 26.
However, the forecasts for January and beyond are much more uncertain because these observation windows have not yet started.
But the forecasts provide a good indication of where the cap might be set if prices do not change much from where they are today.
Fluctuations in wholesale prices could add or remove hundreds, if not thousands of pounds from the final figure.
Regardless, the prediction will pile further pressure on politicians to act. On Thursday, Conservative leadership candidate Rishi Sunak promised to save all households around £200 by cutting VAT on energy.
He also promised more targeted help for vulnerable households, but said he would confirm how much support when the October price cap is finalised later this month.