LONDON (Bloomberg) - Ms Liz Truss, the front-runner to be Britain's next prime minister, is preparing to fast-track an emergency spending package to help people cope with surging energy costs, according to a person familiar with the matter.

The foreign secretary, who is leading in the race to take over from Mr Boris Johnson, could announce the measures before Parliament rises on September 22 for a recess when political parties hold their annual conferences, said the person, who asked not to be named while the details are being finalised.

The move could help deliver a Truss government a political boost in the days after she takes office, potentially eating into the lead the Labour opposition has in the polls.

That could potentially even open the way for a fall general election - though Ms Truss has previously ruled that out.

Ms Truss is eager to act as soon as possible since energy regulators are due to announce an increase on Friday in the bills consumers pay for electricity and natural gas.

Normally, big fiscal measures would come as part of a budget along with estimates from the Office for Budget Responsibility (OBR), the government's fiscal watchdog.

A Truss government would have to short-circuit the usual oversight to deliver action before the Sept. 22 recess, since the OBR usually needs 10 weeks to prepare its estimates.

If she acted that quickly, Ms Truss would be taking a page from the strategy her adversary in the leadership race, Rishi Sunak, followed in setting out aid during the pandemic.

"Immediate action is required," the Truss campaign said in a statement.

"A Truss government would seek to act as soon as possible to help people across the UK, by cutting taxes and introducing a temporary moratorium on energy levies."

And though Mr Sunak's campaign is criticising Ms Truss's plan to act without an OBR forecast, he himself made various big-ticket announcements as chancellor without their analysis.

Those include his £15 billion of extra cost-of-living support in May and the decision to extend the coronavirus furlough programme in December 2020.

As it did for Mr Sunak, announcing a package without the OBR would likely give Ms Truss a political uplift and provide early momentum for her administration, since the aid programme would come without official warnings about long-term affordability.

That would ensure a focus on the giveaway to voters rather than how much it will all cost.

The OBR typically issues two forecasts a year, one in the spring and one in the autumn.

Its last forecast came in March 2022 and only included the impact of the very early days of Russia's invasion of Ukraine.

It had inflation reaching 8.7 per cent in the fourth quarter, below the current rate and the BOE's latest estimate for a peak above 13 per cent.

The chair of Parliament's Treasury Committee, Mel Stride, wrote to Chancellor of the Exchequer Nadhim Zahawi and the OBR to "seek assurance" that work has started on publishing a forecast to be published alongside any budget or significant fiscal event in September.

"Whether such an event is actually called a budget or not is immaterial," Mr Stride said in a statement on Tuesday (Aug 23).

"The reassurance of independent forecasting is vital in these economically turbulent times. To bring in significant tax cuts without a forecast would be ill-advised. It is effectively 'flying blind

Citigroup Says Ms Truss has painted a picture of economic optimism in the race for 10 Downing Street, despite dire warnings from the Bank of England over soaring inflation and a looming recession. Tax Cuts

Her critics say her prospectus of tax cuts won't help the most vulnerable in society and will lead to an increase in government borrowing.

She says her tax-cutting will boost economic growth and reduce inflation.

Officials in the Treasury are currently preparing plans based on the campaign promises of both Ms Truss and Mr Sunak so that they can be swiftly implemented once the new administration takes power, according to another person familiar with the matter.

As it did in May, Treasury officials can ready a major spending package within a matter of weeks, the person said.

Support Sunak's campaign argues that Ms Truss won't be able to deliver both a support package and her billions of pounds of tax cuts.

Mr Brian Griffiths, who was a policy chief for former prime minister Margaret Thatcher and is backing Mr Sunak, wrote in the Daily Telegraph that acting without the OBR would "seem to indicate complete loss of confidence in the policy she is advocating."