Energy bosses will face pressure from ministers about how they can help customers cope with rising bills at a crunch meeting on Thursday.
Chancellor Nadhim Zahawi and Business Secretary Kwasi Kwarteng will press gas and electricity company executives for solutions to the predicted spike in bills over winter.
The summit with utilities bosses, expected to take place in Downing Street, comes after Cornwall Insight predicted bills are set to soar to around £3,582 in October, from £1,971 previously, before rising even further in the new year.
Executives are being asked to submit a breakdown of expected profits and payouts, as well as investment plans for the next three years.
Former prime minister Gordon Brown has suggested scrapping the price cap and negotiating lower rates with energy bosses, according to reports.
Rishi Sunak and Liz Truss continue to face questions about what they will do to help struggling families, while Labour has called for a “loophole” in the oil and gas windfall tax to be closed to raise more support cash.
Ahead of Thursday’s meeting, the Chancellor told reporters: “I think it’s important we all get round the table, I will continue to do the work I need to do as Chancellor, but I also want to challenge them, to say are you making the investment? How can you help your customers? What more can we do together? That’s the reason for the meeting.”
Speaking in Belfast on Wednesday, he added: “What I want to do tomorrow is understand better how they’re committed to that investment in gas, because whatever happens we need energy security and we’ve got a strong strategy that Kwasi and I will continue to push hard.
“The other area I want to look at is some of the energy producers, if you look at the renewable energy producers, the amount that they get paid is linked to gas prices.
“So, they haven’t changed anything they’re doing, they haven’t had any increase in their input costs at all, but they’re getting a much higher return because of the unusually high gas price because of Putin.”
Mr Zahawi also said the Treasury has been preparing “options” for the next prime minister on what further support could be given to people this winter.
Tory leadership candidate Mr Sunak told the BBC that it would be his “moral responsibility” to offer more help with bills if he were selected as prime minister, in particular to pensioners and those on benefits.
Ms Truss appeared to back away from her previous position of providing no more “handouts”, telling GB News she would “do everything I can to support working families” if made prime minister, while emphasising her preference for tax cuts.
Labour has called on the Government to close investment allowances in the energy profits windfall tax, which it has described as a “loophole”, in order to help households pay the bills.
Shadow chancellor Rachel Reeves said: “The Tories are handing oil and gas giants billions in tax breaks, just for them to pass it on to shareholders. The Government should be ashamed this loophole existed in the first place.
“This isn’t right at a time when people are worried sick about how they’ll pay their bills.”
There has been widespread anger at Shell, BP and British Gas owner Centrica announcing bumper financial results while households struggle with soaring bills.
Mr Brown meanwhile told the Guardian that the Government should “pause any further increase in the cap” on bills, and negotiate lower rates with each individual company after examining their balance sheets.
He also suggested ministers should temporarily nationalise any providers that go bust.
“Time and tide wait for no-one. Neither do crises. They don’t take holidays, and don’t politely hang fire – certainly not to suit the convenience of a departing PM and the whims of two potential successors,” the former Labour prime minister said.
He added that Britain should spearhead the international response to the crisis with an emergency G20 meeting.
Mr Brown said: “British ministers – and no one has yet grasped this – should also be leading the way… in demanding coordinated international action with an emergency G20 early in September to address the fuel, food, inflation and debt emergencies.
“These are global problems that can only be fully addressed by globally coordinated solutions.”
Mr Brown, who previously called for the Tory leadership contenders to set aside their differences and work on an emergency plan with Boris Johnson, has been joined in his calls by a boss at one of the UK’s biggest energy companies.
Philippe Commaret, managing director of customers at EDF, said: “We are asking Government and the two Conservative candidates to work with industry so we can find a viable solution for those customers most in need this winter.
“Customers need to know now that help is coming. Delaying a decision will cause anxiety for millions of people, and discussions need to happen now.”
Consumer champion Martin Lewis also made similar calls, telling broadcasters: “I accept the point that Boris Johnson is running a zombie government and can’t do much, but the two candidates – one of them will be our prime minister – they need to get together in the national interest to tell us the bare minimum of what they will do.”
A Government spokesperson said: “We are engaging with the electricity sector to drive forward reforms and to ensure the market delivers better results for people across the UK.
“In the meantime, and as we announced in May, the Government continues to evaluate the extraordinary profits seen in certain parts of the electricity generation sector and the appropriate and proportionate steps to take.”