After the government announced it would reduce funding, an analyst predicted that typical home energy bills might rise to £4,347 annually starting in April.
The projection from Cornwall Insight follows the chancellor's announcement that the two-year energy bill assistance program will end in April.
According to the government, those who are most vulnerable will still be shielded from rising energy costs.
The predictions could alter based on changes in wholesale energy prices.
In an effort to conserve money after the government's mini-budget left a sizable predicted hole in the public finances, the incoming Chancellor, Jeremy Hunt, announced the adjustment to the energy price assistance.
Initially implemented for two years starting on October 1, the government's Energy Price Guarantee restricts the price suppliers can charge for each unit of energy.
The Treasury will now be assessing the funding provided since April, and it will only be in place for six months, covering this winter.
Customers still have to pay for the gas and electricity they use under the present quota. A typical household currently has a yearly bill of £2,500 for using 12,000 kWh (kilowatt hours) of gas and 2,900 kWh (kilowatt hours) of electricity. This is more than the £1,277 from the previous winter.
After a review, the specifics of the help beginning in April will be decided, according to Mr. Hunt. He said that those with lower incomes would receive support and incentives to use less energy.
According to predictions from Cornwall Insight, an average annual energy bill for households who do not receive any assistance could be £4,347 in the spring before falling to £3,722 the following winter.
According to Nigel Pocklington, CEO of renewable energy provider Good Energy, the removal of the two-year cap will bring back "substantial amounts of uncertainty about the future."
About 300,000 people use the services of Mr. Pocklington's company, and he explained that his pledges to the public were based on the government "protecting them from the high levels of energy market through the winter."
He predicted that, based on "current projections without the government support," the typical energy cost will top out at about £4,300 in April and fall below £4,000 by the summer.
When compared to what we typically pay, these rates are incredibly high, he remarked.
Mary Starks, a former executive director for consumers and markets at the energy regulator Ofgem, expressed concern over the move, saying it has returned customers to a state of "grave uncertainty."
Ms. Starks criticized the government for being "extremely confused" about the promise of targeted assistance because it has not been made clear who will be impacted or how it will operate.
"Even expanding universal credit eligibility to everyone is administratively challenging.
"There is more work needed to perform the targeting," she continued, "since there will be a lot more households who will be struggling."
After the prime minister rejected calls to impose a windfall tax on oil and gas businesses, the original plan to control prices for two years—which was estimated to cost up to £150 billion—was to be paid by government borrowing.
Former Chancellor Kwasi Kwarteng, however, followed it up with proposals to lower taxes by almost £45 billion.
The financial market turbulence caused by worries about increased borrowing has affected the mortgage industry, where interest rates on loans have risen to 14-year highs.
On Monday, Mr. Hunt said he was taking "what is essential for economic stability" when he announced the reassessment of the energy support and the cancellation of tax cuts totaling £32 billion.
The Energy Price Guarantee, he continued, had been "the biggest single expense" of Mr. Kwarteng's expansion strategy.