The Government has been accused of issuing "misleading" figures over its pledge to increase NHS funding.
MPs on the Commons Health Committee said the Government's claim that the NHS would receive £8.4 billion by 2020/21 actually translates into £4.5 billion because ministers used a different calculation compared with previous years.
They concluded that health spending "will not increase by as much as expected from official pronouncements", and the Government will not meet its commitment to fund the NHS's vision for the future.
The committee said: "In previous years, spending reviews have defined health spending as the entirety of the Department of Health's budget, but the 2015 spending review defines spending in terms of NHS England's budget, which excludes, for example, spending on public health, education and training.
"Excluding these aspects of spending - which are being cut over the spending review period - is misleading, as these organisations play a vital role in providing front line services to patients, reducing demand through prevention and in training the future workforce.
"We call on the Government to set out the rationale for changing the definition of health spending."
In a wide-ranging report on the state of NHS finances, MPs also said the scale of the funding challenge facing the NHS is "colossal".
It said Government policy has long been to try to curb the increasing patient demand for services - which is partly due to people living longer - by keeping people out of hospital and treating them in the community.
But it said such initiatives have so far failed, with more people admitted to hospital in an emergency, and rising demand for planned admissions and outpatients.
Nigel Edwards, chief executive of the Nuffield Trust, also told MPs there was also a problem with the Government's expectation of realising savings through improved efficiency.
He said: "If you do not give the trusts the money that they need to deliver what they need and you set them efficiency targets that have never been achieved anywhere in the NHS's history, do not be surprised if the income separates from the expenditure over time, particularly against a background of growing demand."
MPs also heard that poor workforce planning has led to an increasing reliance on expensive agency staff, which has contributed to huge hospital deficits.
Anita Charlesworth, of the Health Foundation, told MPs: "The NHS was planning on needing fewer workers; its plans were not to grow the number of workers. We reduced the number of nurses we brought in from other countries in the early years of this decade, we reduced the numbers in training and we have also seen many fewer numbers coming through on return to practice.
"That was predicated, in essence, on both ability to reduce demand - the number of admissions that would come into the system - and a belief that we could work those nurses harder through reducing ratios. That proved to be unsustainable. We saw the numbers of nurses employed falling; then from 2013 onwards, crudely, we re-employed them but we employed them more expensively."
Health Committee chairwoman Dr Sarah Wollaston said cuts to public health grants were also a false economy.
She added: "Similarly, the cuts to health education come at a time when the workforce shortfall is already placing a significant strain on services and driving higher agency costs."