Labour has accused the Conservatives of planning to support businesses with soaring bills on the backs of British families and pensioners instead of energy giants.
Business secretary Jacob Rees-Mogg is set to unveil a multi-billion package of aid on Wednesday amid fears many companies could go to the wall this winter.
Under the plans, millions of businesses across Britain are set to have their energy bills capped for six months from as early as October.
Independent local pubs will also be among a number of “vulnerable” groups who will receive longer-term help, Liz Truss has indicated.
As prices skyrocket some businesses have already been forced to shut their doors. Others have reported projected increases in their energy costs of more than 500 per cent.
Shadow climate change secretary Ed Miliband, said: “This week we will find out who the prime minister believes should carry the financial burden for the energy crisis; hard-working families and pensioners across Britain, or the energy companies making £170bn in excess windfall profits.
“Labour believes that, during a cost of living crisis, the companies making record profits should pay their fair share, and that a windfall tax should be the first port of call for the government, rather than making British families and pensioners pay.
“With one in every four businesses already exposed, the government must urgently set out support what support they will offer businesses across the country.”
He added: “If Liz Truss opposes making the energy companies pay what they owe, she must explain to the public why their taxes will be higher for years to come.”
On a trip to a United Nations summit in New York, the prime minister said soaring energy bills were a "price worth paying" to ensure the UK’s "long-term security" after Russia’s invasion of Ukraine caused costs to spike.
She appeared to defend her rejection of Labour’s call for a windfall tax on energy firms to pay for the support, which polls suggest is popular with the public. Asked by Sky News if she was prepared to be unpopular, she replied: “Yes, yes I am.”
She also insisted the cost to the taxpayer of her energy package, being paid for by borrowing, is "not what has been projected". Reported estimates have ranged as high as £150 billion.
Earlier this month Ms Truss announced a multibillion-pound price guarantee that will cap average annual household bills at £2,500.
A similar scheme for the UK’s businesses and other non-domestic users is expected to be set out on Wednesday.