Spending more on the NHS is not necessarily unaffordable - despite the claims of ministers, a leading health expert says.
A major part of the justification for the overhaul of the NHS was that spending would spiral out of control.
But Professor John Appleby, of the King's Fund, said even a doubling of the budget over 20 years was possible.
Writing for the British Medical Journal website, he said it was about whether the NHS was prioritised even more.
Ministers have spent the past few months arguing that the ageing population, rising cost of drugs and factors like obesity mean spending demands would outstrip what was affordable in the coming years.
In an article in the Daily Telegraph last month, Health Secretary Andrew Lansley suggested on current trends £230bn would need to be spent on health by 2030 compared to the £103bn which is spent now.
He said that figure was one that the country "simply could not afford".
But Prof Appleby, the chief economist at the think-tank, questioned that.
He said taking into account the expected growth in the economy a budget of £230bn would require the health budget to rise at about 4% a year above inflation - only a little more than it has got on average since 1948.
Such rises would bring total health spending, including investment in private health care, to about 12.4% of gross domestic product (GDP) - roughly in line with what high spending countries such as the Netherlands are already spending.
Prof Appleby added: "It is a question of priorities really. It could be afforded, but would just require more money to be spent on health. But we are not talking about ridiculous amounts."
But a Department of Health spokeswoman insisted such spending would constitute a "financial crisis".
She added: "The right approach is to change the way that the NHS spends its budget so that it matches patients' needs better - rather than simply spending much larger sums on patterns of care and service which don't match the changing health needs of the population."