Millions of Britons will find by how much their gas and electricity bills are going up at 11 am tomorrow, regulator Ofgem has said, or a week earlier than expected.
A rise of around 50% was being predicted today to take the energy price cap to around £2,000 from £1,277 currently.
The price cap is the maximum energy supplies can charge customers on default or unfixed tariffs, but for many users it is what they pay and an increase on the scale forecast will see heating bills soar.
Around 15mln households were affected when the energy cap was last changed in October, when it when up by 12%.
Since then almost 4mln customers have had to switch suppliers because their provider has gone out of business.
Not being able to pass on the soaring cost of gas due to the price cap has seen around 27 small suppliers fold.
Reports today suggested that the government is already prepared to alleviate the higher bills with a package of measures that will cost the Treasury £5-6bn.
This will include support for providers as well as a £200 rebate for consumers.
Suppliers will pass on the rebate through lower bills said the reports with the money effectively a loan to providers to be repaid in future years when energy prices start to ease again.
Though it will be announced tomorrow, the new price cap comes into force from the start of April.
No details about how any support scheme would operate have been made available yet said suppliers.
Wholesale gas prices have been hit by what has been described as a perfect storm of soaring demand as the global economy recovers from Covid, outages, low storage capacity and accusations of major European suppliers especially Russia playing politics.
Costs per therm have risen from around 60p at the start of 2021 to 350p currently but were well above 400p at the end of last year.
The rise has sparked calls for a windfall tax on big North Sea gas producers such as Shell, which is scheduled to announce quarterly numbers just hours ahead of the price cap announcement and that is likely to show that the rise in gas and oil prices has been hugely profitable for the company.
Another funding option would be to scrap the 5% VAT levy on heating bills or tinkering with environmental levies, though that might be politically tricky just months after the UK hosted climate change summit COP26.
Rising energy prices have been feeding through into UK inflation providing another headache for the government as it tries to restart the economy after Covid.
The British Retail Consortium said today prices were rising at the faste4est for a decade while inflation generally is running at a thirty-year high even before tomorrow's price cap announcement.