Anita Charlesworth, a chief economist of the Health Foundation charity, urged political parties to take into account the pressures the health service will face in the coming years when they make their pledges on funding.
It comes after Conservative Health Secretary Jeremy Hunt said his party, if elected, would fully fund the plan drawn up by NHS England boss Simon Stevens, which would see £2bn being pumped into the health service every year until 2019/20.
The so-called “Stevens plan” will see a total of £30bn put into the NHS, with £22bn found through efficiency savings and £8 billion in extra spending.
Until now, only the Liberal Democrats had pledged to find the money but Mr Hunt now appears to have signed the Tories up to the so-called “Stevens plan”.
The Health Secretary also suggested that the Conservatives could find efficiency savings amounting to more than £22bn, meaning it would have to spend less to meet the plan.
Asked by the Sunday Times if the Tories would find the full £30bn, Mr Hunt said: “Yes. We’ve demonstrated that we’re as good as our word.
“At the last election we were the only party that promised to protect the NHS budget. We didn’t just protect it, we increased it.
“We said to Simon Stevens, ‘How much do you need for your plan next year, the first year of your five-year plan?’ He said ‘£1.7bn’, and we actually found him £2bn.
“We’re now doing the work as to what the efficiency savings are. The gap might be more than £8bn, it might be less.”
Mrs Charlesworth, whose independent charity works to “continuously improve the quality of healthcare in the UK”, said the £30bn funding gap that will exist by 2020 could only be closed “if public funding for health rises by 1.5 per cent a year in real terms and the NHS achieves a rate of productivity growth of 2-3 per cent a year”.
She said: “However, this is much higher than the recent rate of productivity growth and there are substantial challenges still to overcome to ensure the promised £8bn will enable the NHS to sustain, let alone improve, the quality of care.
“The period between 2010/11 and 2020/21 will be the most financially austere decade in NHS history and spending pressures will continue beyond the next parliament.”
Liberal Democrat campaign spokesman, Lord Paul Scriven, claimed yesterday that the Conservatives had not credibly set out how they would pay for the Stevens plan.
The Lib Dems have committed to investing £1bn in the NHS in real terms in 2016/17, paid for by restricting reliefs on capital gains tax and scrapping the employee “shares for rights” scheme introduced by the coalition.
The party said it would then increase health spending in line with economic growth after balancing the deficit in 2017/18, meaning the extra £8bn will be achieved by 2020/21, taking into account the £1.7bn already committed by the coalition.
Shadow Health Secretary Andy Burnham claimed that the “extreme” cuts planned by the Tories for the next three years would mean they cannot protect the NHS.
He reiterated Labour plans to plough £2.5bn a year into the health service, using money raised from a mansion tax on homes worth £2m and more.
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