LABOUR has dismissed as an “absolute work of fiction” Conservative claims that it is planning to spend £1.2 trillion of taxpayers’ money over five years if it won the General Election.

As the campaign rhetoric stepped up a gear, Sajid Javid warned that a Jeremy Corbyn government would introduce “eye-watering” levels of spending, amounting to “some £650 million extra a day or something like the entire NHS budget for nine years".

“It will be absolutely reckless and will leave this country with an economic crisis within months, not years," declared the Chancellor.

The calculation set out the “true cost of Corbyn’s Labour,” insisted Mr Javid, who oversaw the costings.

They cover Labour’s policy to renationalise rail, energy and water as well as the plan to introduce a four-day week, which Mr Javid described as amounting to a “truly frightening spending splurge,” that would leave the country on the “brink of bankruptcy”.

The Chancellor argued Britain could “not afford Corbyn's spending spree," which, he warned, would "undo all hard work of British people in recent years".

But his Labour Shadow, John McDonnell, was equally assertive in his denial.

He condemned the analysis as a "ludicrous piece of Tory fake news" and an "incompetent mish-mash of debunked estimates and bad maths cooked up because they know Labour’s plans for real change are popular".

His colleague, Andrew Gwynne, dismissed the Conservative claims as an “absolute work of fiction,” declaring: “You can’t trust a word Boris Johnson says.”

Asked what the true figure for Labour spending was, the Shadow Communities Secretary told BBC TV’s Andrew Marr Show the manifesto was still being drawn up but would be “fully costed and transparent”.

The prospectus, due to be agreed next Saturday, would be an “ambitious and transformative” Attlee-like programme, insisted Mr Gwynne.

It is suggested Labour is considering plans for a universal basic income.

Last week, analysts warned both the Conservatives and Labour had “abandoned restraint” with Sir Nicholas Macpherson, the former Treasury mandarin, accusing them of “fiscal incontinence”. While the Tories are planning to spend an extra £20bn a year, Labour is hoping to outlay an extra £55bn.

On Monday, analysts predicted the Government would receive a boost as official figures for the latest quarter look set to confirm Britain has avoided a recession with growth between July and September likely to be 0.4 per cent. The previous quarter saw a contraction of 0.2 per cent.

It was suggested Mr Javid is keen to hold his own televised head-to-head debate with Mr McDonnell to face questions about their parties’ respective spending plans. Labour sources said they were happy to see such a clash go ahead. Both the Conservative and Labour manifestos are due to be launched in the next two weeks.

When pressed on the Tories’ own spending plans, the Chancellor insisted they would be restrained by a “fiscal anchor” with the pledge that debt would be lower at end of the next five-year Parliament.

When quizzed about whether the Conservative manifesto would raise the income tax threshold - as promised by Mr Johnson in his Tory leadership campaign, Mr Javid failed to give a direct answer but declared: “I believe in low taxes.”

However, he stressed: "With our plans, because they are properly costed, and by the way - whether it's a tax pledge or anything else - we will be clear about how we will be funding that and that will be absolutely inside our fiscal rules.”

Later his Government colleague, Kwarsi Kwarteng, the Business Minister, was unable to put a price on Conservative pledges, saying: "I'm not going to bandy around figures."

Meanwhile, the Liberal Democrats challenged the two main parties to submit their election manifestos to the Office for Budget Responsibility, the independent forecaster, to be costed in their battle to “splash the cash”.

Sir Ed Davey, the party’s Treasury spokesman, said: "The cash commitments that are being thrown around by the two old parties need to be subject to proper scrutiny.

"These flush figures are a knee-jerk reaction fuelled by fantasy Brexit-economics, failing to acknowledge the drain on our resources that Brexit has, and will continue to be on our public services.”

He stressed that party manifestos needed to be independently assessed and costed by the OBR, so that the public could be confident that flagship policies could be delivered.

"The Liberal Democrats are committed to building a brighter future and are more than prepared to submit our manifesto to the OBR,” declared Sir Ed, adding: “Are Labour and the Tories?"

The spending clash came as two polls placed the Tories ahead.

A snap by YouGov placed the Conservatives unchanged on a week ago with 39 points, Labour was down one on 26, the Lib Dems were up one on 17 while Nigel Farage’s Brexit Party was up three on 10. An Opinium poll gave the Tories a 12-point lead over Labour, 41 to 29, with the Lib Dems on 15 and the Brexit Party on six.

Elsewhere, Electoral Calculus’s poll of polls so far this month, involving more than 8,200 people, predicted a Conservative majority of 90. It gave the Tories 370 seats, up 52 on the 2017 election, Labour on 186, down 76, the SNP on 48, up 13, and the Lib Dems on 25, also up 13.

In a separate development, Jonathan Bartley, the Greens’ co-leader, said he believed his party was set for its biggest vote ever, as despite movement on the climate crisis by other parties, it was still leading the way on the issue. “The size of the proposals for climate by Labour are just a quarter of the size of what we are proposing in terms of our Green New Deal,” he said.