The new Tory leader is to be announced at lunchtime today, with Liz Truss widely expected to defeat Rishi Sunak in the race to succeed Boris Johnson as prime minister.
The winner will take office tomorrow, after formal appointment by the Queen.
The Times says today that Ms Truss is set to announce a vast support package to deal with surging energy costs as her allies and officials discuss plans for a gas and electricity price freeze with industry leaders.
The cost of dealing with growing energy bills this winter is understood to be on the scale of the Covid furlough scheme.
Industry sources said that a price freeze for consumers was "the only conversation that anyone was having with the government", including discussions involving Kwasi Kwarteng, who is expected to be Ms Truss's chancellor.
"The plan is to introduce some kind of artificial price cap for consumers combined with a mechanism for reimbursing suppliers," one source said. "Plans are reasonably-well advanced and involve not just civil servants but also ministers lined up for jobs by Ms Truss."
The level of the price cap has not been set - and businesses, particularly hospitality and retail, would need separate support, the source added.
Package could cost more than furlough scheme
One senior government figure said the scale of the package being looked at would "at least" be in the region of the £69billion cost of the furlough scheme and "could be more". "No one has come up with any option to do it for less," the source said.
The new PM will inherit a flagging economy, with inflation at a 40-year high.
Foreign Secretary Ms Truss has promised to announce further help to shield consumers within a week of taking over.
She also plans to deliver £30billion in tax cuts through an emergency Budget later this month, arguing the UK's tax burden is behind sluggish growth.
Her leadership rival, former chancellor Mr Sunak, has signalled he believes he has lost, saying his job "now is just to support a Conservative government".
The BBC says Ms Truss plans to temporarily scrap green levies on energy bills and reverse the rise in National Insurance introduced during Mr Johnson's tenure.
On Sunday, the foreign secretary admitted unpicking the National Insurance rise would benefit higher earners more, but said it was justified because it would boost the economy overall.
Low economic growth
Speaking to the BBC's Laura Kuenssberg, she blamed a focus on distributing wealth through taxes for low economic growth over the past two decades.
Ms Truss has previously described the idea of a freeze on energy prices as a "sticking plaster" and argues more needs to be done to help the UK boost its domestic sources of energy.
She said any further support for consumers would have to go "hand in hand" with efforts to boost nuclear energy, fracking for shale gas and more oil and gas drilling in the North Sea.
As well as tax cuts, Ms Truss has pledged to deliver low-regulation investment zones and bring about the biggest increase in defence spending in decades.
The seven-week leadership contest brings to an end Mr Johnson's turbulent three years in office.
He was forced out in July by a ministerial revolt over a string of scandals, after leading the Tories to a landslide victory at the 2019 election.
The original field of 11 contenders to succeed him was whittled down to two in a series of Tory MP ballots, with the final pair going into a run-off to be decided by the party membership, which stands at about 160,000.
Although Mr Sunak had the most support among Tory MPs, he has trailed Ms Truss in opinion polls of the party grassroots.