The boss of one of the largest and busiest NHS trusts in the UK has resigned in protest at the Government’s “unrealistic expectations” on saving costs.

Bob Kerslake, former chairman of the King’s College hospital board in London, which treated victims of recent terror attacks and the Grenfell Tower fire, stepped down from his post while calling for a “fundamental rethink” of how the NHS is funded.

In an op-ed for the Guardian, Mr Kerslake, the former head of the civil service, claimed the Government was in denial about how much money the NHS needs.

“My two and half years at King’s have been in equal parts inspiring and frustrating.

“There are undoubtedly things that I and the trust could have done better – there always are – but fundamentally our problems lie in the way that the NHS is funded and organised. We desperately need a fundamental rethink. Until then, we are simply kicking the can down the road,” he wrote.

Mr Kerslake had been in the role for less than three years.

Everyone the Government blames for the NHS crisis – except themselves Show all 6 1 /6 Everyone the Government blames for the NHS crisis – except themselves Everyone the Government blames for the NHS crisis – except themselves The elderly “We acknowledge that there are pressures on the health service, there are always extra pressures on the NHS in the winter, but we have the added pressures of the ageing population and the growing complex needs of the population,” Theresa May has said. Waits of over 12 hours in A&E among elderly people have more than doubled in two years, according to figures from NHS Digital. Getty Everyone the Government blames for the NHS crisis – except themselves Patients going to A&E instead of seeing their GPs Jeremy Hunt has called for a “honest discussion with the public about the purpose of A&E departments”, saying that around a third of A&E patients were in hospital unnecessarily. Mr Hunt told Radio 4’s Today programme the NHS now had more doctors, nurses and funding than ever, but explained what he called “very serious problems at some hospitals” by suggesting pressures were increasing in part because people are going to A&Es when they should not. He urged patients to visit their GP for non-emergency illnesses, outlined plans to release time for family doctors to support urgent care work, and said the NHS will soon be able to deliver seven-day access to a GP from 8am to 8pm. But doctors struggling amid a GP recruitment crisis said Mr Hunt’s plans were unrealistic and demanded the Government commit to investing in all areas of the overstretched health service. Getty Everyone the Government blames for the NHS crisis – except themselves Simon Stevens, head of NHS England Reports that “key members” of Ms May’s team used internal meetings to accuse Simon Stevens, head of NHS England, of being unenthusiastic and unresponsive have been rejected by Downing Street. Mr Stevens had allegedly rejected claims made by Ms May that the NHS had been given more funding than required. Getty Everyone the Government blames for the NHS crisis – except themselves Previous health policy, not funding In an interview with Sky News’s Sophy Ridge, Ms May acknowledged the NHS faced pressures but said it was a problem that had been “ducked by government over the years”. She refuted the claim that hospitals were tackling a “humanitarian crisis” and said health funding was at record levels. “We asked the NHS a while back to set out what it needed over the next five years in terms of its plan for the future and the funding that it would need,” said the Prime Minister. “They did that, we gave them that funding, in fact we gave them more funding than they required… Funding is now at record levels for the NHS, more money has been going in.” But doctors accused Ms May of being “in denial” about how the lack of additional funding provided for health and social care were behind a spiralling crisis in NHS hospitals. Getty Images Everyone the Government blames for the NHS crisis – except themselves Target to treat all A&E patients within four hours Mr Hunt was accused of watering down the flagship target to treat all A&E patients within four hours. The Health Secretary told MPs the promise – introduced by Tony Blair’s government in 2000 – should only be for “those who actually need it”. Amid jeers in the Commons, Mr Hunt said only four other countries pledged to treat all patients within a similar timeframe and all had “less stringent” rules. But Ms May has now said the Government will stand by the four-hour target for A&E, which says 95 per cent of patients must be dealt with within that time frame. Getty Images Everyone the Government blames for the NHS crisis – except themselves No one Mr Hunt was accused of “hiding” from the public eye following news of the Red Cross’s comments and didn’t make an official statement for two days. He was also filmed refusing to answer questions from journalists who pursued him down the street yesterday to ask whether he planned to scrap the four-hour A&E waiting time target. Sky News reporter Beth Rigby pressed the Health Secretary on his position on the matter, saying “the public will want to know, Mr Hunt”. “Sorry Beth, I’ve answered questions about this already,” replied Mr Hunt. “But you didn’t answer questions on this. You said it was over-interpreted in the House of Commons and you didn’t want to water it down. Is that what you’re saying?” said Ms Rigby. “It’s very difficult, because how are we going to explain to the public what your intention is, when you change your position and then won’t answer the question, Mr Hunt”. But the Health Secretary maintained his silence until he reached his car and got in. Getty

He also tweeted: “I do not do this lightly as I love King's but believe the Govt & regulator are unrealistic about the scale of the challenge facing the NHS & the Trust. I want to pay tribute to the staff & their excellent patient care.”

Mr Kerslake’s departure comes days before the trust is anticipated to be put into “special measures” as it failed to stick to its budget this year.

Budget 2017: Hammond promises NHS £350m patch for winter

Mr Kerslake argued that the trust had made savings of £80 million in each of the last two years, but the trust struggled since taking on responsibility for Bromley’s Princess Royal University hospital in 2014. He added that rising demand, squeezed spending and increased costs caused financial strain.

King’s has built a reputation at home and abroad for pioneering treatment in areas such as liver disease, diabetes and neurosciences.

His words follow NHS chief executive Simon Stevens' call for an emergency cash injection of £4 billion.

Chancellor Philip Hammond dismissed the call, saying public services and government departments always came to him before a budget asking for “very large numbers”, hinting that otherwise “Armageddon will arrive”.