The NHS has been left with a "Boris-shaped black hole" in its finances as analysis of the Budget found the health service would receive nearly £70bn less after leaving the EU than Brexiteers promised, campaigners have claimed.

Chancellor Philip Hammond announced £2.8bn of one-off funding for the NHS by 2020 in his set-piece statement on Wednesday - including a £350m boost to see the health service through the winter.

Analysis by pro-EU campaigners Open Britain found the Budget would leave the NHS nearly £70bn worse off than it would have been after the Leave campaign's infamous promise to claw back £350m of EU cash a week to spend on the NHS.

Boris Johnson and other Brexiteers used the widely-disputed figure as a campaign tool during the referendum and the Foreign Secretary attracted fresh criticism for repeating the claim in a 4,000-word article in September outlining his personal Brexit vision.

If this promise had been delivered, the NHS would have received an extra £72.8bn in the four years after Britain leaves the European Union, rather than the expected £3.4bn from 2019/20 to 2022/23, the group said.

Labour MP Heidi Alexander, a supporter of Open Britain, told The Independent: “Our NHS is facing a Boris-shaped black hole in its budget.

"He and his cronies promised the British people £350 million more a week for the NHS after Brexit.

"But now we learn the Government of which he is a member will only provide a fraction of that money.

“As winter approaches, our National Health Service is already on life support.

"A fifth of doctors from the EU are making plans to leave, we face a shortfall of GPs, and hospitals are reeling from years of cuts."

She urged Mr Johnson to apologise for using the figure, which was dubbed a "clear misuse of statistics" by the head of the UK Statistics Authority.

Sir David Norgrove has previously explained that the £350m statistic relates only to what the UK currently pays to the EU and does not include the money that Britain receives in return.

Other prominent Leave campaigners including former Ukip leader Nigel Farage and David Davis, the Brexit Secretary, have distanced themselves from the figure.

Brexit: the deciders Show all 8 1 /8 Brexit: the deciders Brexit: the deciders European Union's chief Brexit negotiator, Michel Barnier Getty Brexit: the deciders French President Emmanuel Macron Getty Brexit: the deciders German Chancellor Angela Merkel Reuters Brexit: the deciders Commission President Jean-Claude Juncker EPA Brexit: the deciders The European Parliament's chief Brexit negotiator Guy Verhofstadt Getty Brexit: the deciders Britain's Prime Minister Theresa May Getty Images Brexit: the deciders Britain's Chancellor of the Exchequer, Philip Hammond PA Brexit: the deciders After the first and second appointed Brexit secretaries resigned (David Davis and Dominic Raab respectively), Stephen Barclay is currently heading up the position PA

The Chancellor, who backed Remain, acknowledged the "NHS is under pressure right now" during his Budget giveaway, which came days after he rejected a plea from NHS England's chief Simon Stevens for a £4bn injection for the health service.

In a sign of growing frustrations within the NHS, Mr Stevens also called on the Government to give the health service the money it was promised during the EU referendum.

Mr Hammond has also faced criticism for failing to provide extra funds for social care in the Budget, forcing cash-strapped councils to dig into their emergency reserves to fund services.

Analysis by the Office for Budget Responsibility (OBR) shows that English councils withdrew £1.4bn from emergency reserves last year.