Liz Truss is considering a freeze on energy bills in an effort to help households cope with rising living costs. 

The Foreign Secretary is widely tipped to win the Conservative leadership race as the UK's next prime minister will be officially announced on Monday.

Liz Truss or Rishi Sunak will be named the party's new leader at 12.30pm today, before being formally appointed by the Queen at Balmoral on Tuesday.

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 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.

Ms Truss had used an interview on the BBC on Sunday to insist that she would within a week reveal fresh supports for struggling households, but repeatedly declined to spell out what those support measures might look like.

“Before you have been elected as prime minister, you don’t have all the wherewithal to get the things done,” she told the Sunday with Laura Kuenssberg programme.

“This is why it will take a week to sort out the precise plans and make sure we are able to announce them. That is why I cannot go into details at this stage. It would be wrong.”

It comes as Kwasi Kwarteng, widely tipped to be the next Chancellor if Ms Truss is successful on Monday, used an article in the Financial Times to stress 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.

“The OECD has said that the current government policy is contractionary, which will only send us into a negative spiral when the aim should be to do the opposite. But I want to provide reassurance that this will be done in a fiscally responsible way. Liz is committed to a lean state and, as the immediate shock subsides, we will work to reduce the debt-to-GDP ratio over time,” he wrote.

Mr Kwarteng, a close political and ideological ally of Ms Truss, offered a vision for how he would operate the Treasury as he said that the next Government would be “decisive and do things differently”.

“That means focusing on how we unlock investment and growth, rather than how we tax and spend. It is about growing the size of the UK economy, not burying our heads in a redistributive fight over what is left,” he wrote.

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 benefitting higher earners.

She told the BBC “growing the economy benefits everybody” and it is “wrong” to look at everything through the “lens of redistribution”.

Scottish Labour leader Anas Sarwar was among those who have called for an energy price freeze. 

Hours before the announcement, Mr Sarwar urged the new prime minister to take immediate action. 

He added that, regardless of who wins the contest – in which Ms Truss is the frontrunner – the new premier will be “Boris Johnson with neater hair, but without the jokes”.

“Today just 160,000 Tory members will inflict a new prime minister on our country,” he said.

“Liz Truss or Rishi Sunak? It doesn’t matter. It’s just more of the same. The same lies, deceit and failures. Whoever wins, it’s just Boris Johnson with neater hair, but without the jokes.

“Meanwhile, families worry about how they will afford spiralling bills and sky-high energy costs.

“The cost-of-living crisis is the number one issue facing families today and the Tories have no answers.

“We won’t see the scale of change we need as long as this failing, out-of-touch Tory government is in office.

“The first thing the prime minister needs to do is freeze energy prices. The second thing they need to do is call a general election.”