Boris Johnson's successor will be confirmed on Monday after a lengthy, and sometimes bitter, Tory leadership race.
Liz Truss is widely tipped to win, as she has consistently outperformed former Chancellor Rishi Sunak in the polls.
And Ms Truss is strongly considering freezing energy bills in a bid to ease the burden on households this winter, according to reports.
Having made tax cuts a key priority during her leadership campaign, Ms Truss had remained tight-lipped into Sunday about what kind of support package she might introduce.
It comes as the UK faces the prospect of soaring energy bills and a worsening cost-of-living crisis.
But reports in The Daily Telegraph and The Times on Monday suggest Ms Truss will likely introduce an energy bills freeze in some form.
The Times reports the package could be on the scale of the furlough scheme introduced by then-Chancellor Rishi Sunak when the Covid-19 pandemic struck, while the Telegraph suggests the specifics of such a policy are still being debated.
It comes as Kwasi Kwarteng, widely tipped to be the next Chancellor if Ms Truss is successful on Monday, stressed that the next Government will behave in a “fiscally responsible” way.
Mr Kwarteng, the current Business and Energy Secretary, appeared to try to address concerns about Ms Truss’ tax-cutting strategy, which rival Mr Sunak warned would only worsen the grim economic situation facing the UK.
Mr Kwarteng said that there would be “some fiscal loosening” in a Truss administration to help households through the winter, stressing that it was the “right thing” to do.
He said that the UK does not need “excessive fiscal tightening”, pointing to the UK’s ratio of debt to GDP compared to other major economies.
His comments directly echo those of Ms Truss on Sunday, as she insisted that her plan to reverse the rise in National Insurance is “fair” despite it directly benefiting higher earners.
The announcement of the next Conservative leader is scheduled for early afternoon at an event in central London on the same day Parliament returns.
Both candidates have spent the last several weeks traversing the country and taking part in hustings in a bid to win over the 200,000 party members charged with choosing the next Conservative leader.
The winner will emerge as the third Conservative prime minister since 2016, when David Cameron quit after losing the Brexit vote, and will oversee a party that remains bitterly divided about the legacy of Mr Johnson and its future direction.
Voting closed last Friday and the contest will draw to an end when the formal announcement is made by Sir Graham Brady, chairman of the 1922 Committee of Conservative backbench MPs.
The new leader is expected to make a speech following the announcement, before spending the rest of the day finalising their choices for Cabinet and wider ministerial roles and writing their first prime ministerial speech.
Once the result is known, Mr Johnson and his successor will go to Balmoral in a break from tradition.
Described by allies as likely to be a “very sad” occasion for the outgoing PM, the Queen will receive Mr Johnson on Tuesday at her Aberdeenshire home, where he will formally tender his resignation.
This will be followed by an audience with the new Tory leader, where she or he will be invited to form a government.
Prime Minister Boris Johnson outside Downing Street
Dominic Lipinski
Rishi Sunak and Liz Truss
PA