The Government has been accused of issuing "misleading" figures that double the actual amount of NHS spending.
MPs on the Commons Health Committee said that claims that the NHS would receive £8.4 billion by 2020/21 actually translates to £4.5 billion because ministers used a different calculation compared to previous years.
The committee said the actual figure will mean that the Government will not meet its commitment to fund the NHS's vision for the future.
In a report on the state of NHS finances, MPs said the funding challenge is "colossal" and that government policy has long been trying to curb patient demand for services by 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, told MPs there was a problem with the Government's expectation of realising savings through improved efficiency.
MPs heard that an increased reliance on expensive agency staff has contributed to huge hospital deficits.
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."