The former head of the NHS this morning launched an extraordinary public attack on Labour for being the only party not to commit to an extra £8billion a year for the health service. Sir David Nicholson said it was crucial that all the main political parties backed the NHS’s five-year plan, which calls for a 7 per cent boost to the health budget by 2020. David Cameron and Nick Clegg have pledged to find the cash – but Ed Miliband has refused. Warning:Sir David Nicholson, the retired head of NHS England, has warned of a 'substantial financial problem' at the heart of the NHS and says it is being ignored by politicians . Speaking this morning, Sir David said: ‘That £8billion needs to be available and all of the parties but Labour have signed up. But it’s important we get all the parties signed up. I think it will be helpful for the NHS if Labour agree to sign it.’ Sir David said it was vital for the NHS for there to be a ‘political consensus’ guaranteeing its budget. He said once the NHS knew what its budget was going to be it could start tackling the growing black hole in its finances. ‘They must make sure we are not building on sand but on a stable financial base,' he said. Health Secretary Jeremy Hunt this morning weighed in behind Sir David - admitting that the NHS faced 'a significant financial challenge over the next Parliament'. But he said: 'That’s why we have committed to finding at least an extra £8billion a year by 2020. This is the amount, Simon Stevens the current Chief Executive of the NHS said the service would need.' Mr Hunt added: 'Labour must explain why they won't find the money the NHS says it needs.' Deputy Prime Minister Nick Clegg also backed Sir David's remarks. He said: 'The NHS does need more money. Now, it’s David Nicholson’s successor, as it happens, Simon Stevens identified this number: £8billion by the end of the next parliament. 'He and David Nicholson are quite right to expect political parties to explain how they’re going to come up with that money.' Deputy Prime Minister Nick Clegg, appearing this morning on LBC, backed Sir David's intervention . Sir David's intervention came after Mike Dixon, leading GP and Chair of the NHS Alliance also laid into Labour. He said: ‘The NHS will be extremely worried by the lack of political consensus around the £8billion funding for the NHS’ five-year plan. 'NHS leaders have been clear that this is the minimum amount needed to maintain current service provision. 'It’s not rocket-science to predict the impact on the NHS if this commitment is not met: patients would face longer waits, services would face severe cuts and rationing, and many hospitals and GP practices would struggle to survive in their current form.’ Sir David accused politicians of ignoring a black hole in the NHS budget to boost their election chances. He warned that there was a 'substantial financial problem' at the heart of the NHS and claimed the financial peril it faces will soon be 'crystal clear'. The former NHS chief said that politicians were talking about spending more money rather than addressing existing funding gaps. Sir David was called the Man With No Shame after he refused to resign over the Mid-Staffordshire Hospital Trust scandal and retired with a gold-plated pension last year. Before he left the NHS he spoke of his 'bitter regret' over not speaking to affected patients and their families during the Stafford Hospital scandal, where 1,200 died, but he refused to quit. David Cameron was back on a building site  yesterday, while Ed Miliband was pictured outside the BBC in central London . Sir David Nicholson has worked in the NHS since 1977, the same year he joined the Communist party. After working in mental health for a decade, he rose through the ranks to become chief executive of several bodies including the Shropshire and Staffordshire Strategic Health Authority at the time of the care scandal in which up to 1,200 people died. In 2006 he became chief executive of the whole of the National Health Service, in charge of a £90billion budget and 1.3million staff. He claimed £50,000-a-year in expenses on top of a salary of his £211,000 salary, £20,000 bonus and around £47,000 of 'benefits in kind'. The package was criticised at a time when his 'Nicholson Challenge' was imposing £20billion in efficiency savings on the NHS. He insisted he had to travel by first-class to do his job, but refused to explain to MPs why his expense claims included 41 first-class trips to Birmingham, where his 35-year-old wife lives with their baby daughter. He was also accused of overseeing a culture of fear within the NHS where hospitals fiddle their figures and whistleblowers are prevented from speaking out. In a three-year period under his rule a total of £14.7 million was spent on almost 600 'compromise agreements' preventing ex-employees from speaking out. A year after his retirement he has re-emerged to warn of problems with the NHS' finances. He told the BBC: ''I have not heard in most of the conversations politicians are having at the moment about what they're going to do about that financial hole. 'They want to talk about extra services and extra investment when actually there is a problem there to face.' The former head of NHS England also cast doubt on Tory and Liberal Democrat plans to fund the health service. Sir David Nicholson said the so-called 'Stevens plan' both parties have signed up to, which involves the government injecting £8 billion cash into the NHS while gaining £22 billion from efficiency savings, will be difficult to implement. Labour is the only main party which has not signed up to the five-year plan drawn up by current NHS England chief executive Simon Stevens, instead favouring a £2.5 billion Time to Care fund paid for by a mansion tax and tobacco levies. Sir David told BBC Radio 4's Today programme: 'What the public is being told at the moment is that 'we'll give you a bit of extra money and everything will be fine' and that actually these managers can deliver £22 billion and then everything will be fine. 'So in a sense if they find it difficult to do that and I think most of them will, I think they are going to be blamed.' Sir David launched 'Nicholson's challenge' in 2009, when he ran NHS England, and urged staff to find £20billion in 'efficiency savings' by 2015 - but it failed. He says the situation today is similarly grave and warned that the NHS will have to take 'emergency action' such as freezing recruitment. Savings could mean that patients could be forced to wait longer waits for treatment, more expensive drugs may not be used and it will be even harder to see a GP. Sir David was one of the most criticised civil servants of recent times when he was the £211,000-a-year head of NHS England. In that period he defied calls to resign from MPs and campaigners over his role in the Mid Staffordshire Hospital scandal, where hundreds died through neglect. Relatives described how elderly patients became so thirsty they resorted to drinking dirty water from vases, while nurses said they left wards in tears because care was so poor. Sir David was accused of not taking action while in charge of the regional health body overseeing the trust, and later when appointed NHS chief executive in 2006. In fact at the height of the scandal, in October 2005, he toured the hospital wards and wrote a glowing letter to managers praising them for hitting targets. But he has repeatedly insisted that at the time he had 'no idea' of the unfolding scandal and maintained that the failings were 'system wide'. He came under further pressure when it emerged he had ignored the concerns of two whistleblowers about another trust, University Hospitals Lincoln, where 670 patients may have died needlessly. Sir David became known as the 'man with no shame' because of his stance over the scandals and his pension pot is  likely to be more than £2million. He said last night: 'Other people will make judgements about my record. I think I made a contribution to improving services. But obviously I regret people suffered. I regret patients did not get the best possible care.'
Sir David Nicholson called on Labour to commit to spending extra on NHS .
He said the NHS has a 'substantial financial problem' which needs sorting .
The former head of NHS says black hole will be 'crystal clear' after election .
Sir David was called the 'Man With No Shame' for refusing to quit his job .
1,200 died because of poor care in Stafford while he ran regional body .