Patients are being denied fair access to drugs and treatment because of wide variations in NHS spending, a report out today has found.
The King's Fund said "serious questions" needed to be asked after its study revealed a postcode lottery in three key areas.
It discovered that spending on mental health and cancer in some areas of England is four times that in other places.
Even when the socioeconomic needs of local people are taken into account, there is still wide variation in primary care trust spending on mental health, cancer and circulatory problems.
After adjusting for such factors, Islington PCT spends £259 per head on mental health, four times the £66 spent by Bracknell Forest.
The proportion of a PCT's budget spent on cancer also varies widely across England - from three per cent to more than ten per cent of the overall budget, the think tank's report said.
Daventry And South Northamptonshire PCT spends £132 per head on cancer and tumours but the Heart of Birmingham Teaching PCT spends around a quarter of that, at just £35 per head.
Spending on circulatory problems, including coronary heart disease, also varies widely.
Wyre PCT in Lancashire spends £173 per head but City and Hackney PCT in east London spends less than half of that, at £68 per head.
PCTs are in charge of around 80 per cent of England's NHS budget, amounting to about £58 billion a year.
The report, Local Variations in NHS Spending Priorities, said the three Government priority areas of heart disease, cancer and mental health consumed the largest share of PCT spending.
The analysis focuses on data from 2003/04 to 2004/05 and pointed out there was was a two-fold difference in mental health spending per head across 90 per cent of PCTs.
Mental health absorbed £7 billion - around 11 per cent of PCT spending - which was twice the amount spent on cancer care. King's Fund chief economist Professor John Appleby said: "This new data is very revealing, and raises serious questions about the consistency of decisions PCTs make.
"Variations in clinical decisions about who and when to treat, and what treatment to provide, and differences in the efficiency of hospitals, contribute to the variations in PCT spending."
