A no-deal Brexit could lead to “another prolonged period of austerity," the UK’s foremost economic think-tank has warned.

The Institute for Fiscal Studies in its traditional post-Budget analysis claimed Philip Hammond’s "gamble" with the public finances could lead to higher borrowing and debt in coming years, it was “all but inevitable” that there would be tax rises in the longer term to pay for the pressure on the NHS from Britain's ageing population and that any expectation the Chancellor would meet his target of eliminating the deficit by the mid-2020s was "for the birds".

Paul Johnson, the think-tank’s director, said the figures in Mr Hammond’s £100 billion giveaway Budget would “go out of the window” if Britain crashed out of the EU without a deal given they were based on a “softish kind of Brexit”.

He suggested that if there were no withdrawal agreement with Brussels, then the Chancellor would turn to “splashing more cash” in the short term.

Mr Johnson told the London Evening Standard: “The Chancellor would probably try to support the economy by cutting taxes or increasing spending immediately but would then have to claw that back through potentially another prolonged period of austerity.”

During the Commons Budget debate, opposition MPs warned that Britain could face a decade of "Brexit austerity".

Noting how the country was “staring into the abyss that is Brexit," the SNP’s Kirsty Blackman said she could “not think of time a time in the past where a country has committed such a foreseeable act of economic self-harm”.

The Aberdeen North MP noted that the country was promised £350 million a week for public services and that “we won't be bought off with a commemorative 50p coin".

Intervening, the Liberal Democrats’ Sir Ed Davey asked: "Does she agree with me that after a decade of Lehman austerity, we could be facing a decade of Brexit austerity?"

Ms Blackman replied: "I absolutely agree," and referred to the "economic catastrophe that is coming down the line" as a result of Brexit before arguing that staying in the EU was the best option for the economy followed by staying in the single market and customs union.

Labour’s John McDonnell said the Budget had served only to reveal how "out of touch" with reality the Conservative Government was.

"Austerity is not ending. In the weeks and months ahead people will recognise that the Prime Minister's promise has been broken,” the Shadow Chancellor insisted.

For the UK Government, Liz Truss, Chief Secretary to the Treasury, later said the Budget showed how the hard work of the British people was paying off and that austerity was coming to an end.

She added: “But we are also clear that discipline remains and that is the dividing line in British politics today; a Conservative Government delivering on people’s priorities and getting the debt down or the real gamble, the Jeremy Corbyn party that would tax and borrow one thousand billion pounds and take the country back to square one.”

Meanwhile in Norway, Theresa May rejected the notion that the Chancellor's giveaway Budget was designed to pave the way for a snap general election.

Asked at a press conference in Oslo, where she was attending the Northern Future Forum, if she was planning to ask voters to go back to the polls, the Prime Minister responded emphatically: "No. We are not preparing for another general election. That would not be in the national interest."

Mrs May had several bilateral meetings with Scandinavian counterparts to discuss the latest developments in the Brexit talks.

In other developments:

*the Conservatives and SNP clashed at the Commons Scottish Affairs Committee when Tory MPs accused Fergus Ewing, the Scottish Rural Economy Secretary, of leaving farmers in limbo by refusing to let the UK legislate for Scotland on agriculture but he hit back claiming the Tories were “scaremongering” by suggesting a gap in the statute book could see farmers miss out on vital subsidy payments;

*the SNP’s Alison Thewliss, noting how the Government had stumped up money to help repair infrastructure in the wake of a city centre fire in Belfast but not in Glasgow, said: “The Tories are too busy buying DUP votes by investing in Belfast whilst completely ignoring those in similar circumstances in Glasgow”;

*Lynne Owens. Director General of the National Crime Agency, warned British authorities could be left in the dark over the presence in the country of suspects wanted for serious crimes overseas if access to EU intelligence data were lost after Brexit and

*Immigration Minister Caroline Nokes told MPs British tourists could face delays at European airports after Brexit and that the prospect of UK travellers ending up in "rest of the world" queues was "not unrealistic" and

*Ms Nokes also said, if there were a no-deal Brexit, employers would be expected to check whether EU nationals had the right to work in the UK but when asked how they would make the checks, she said she did not know and would write to the Commons Homes Affairs Committee.