SHOULD funding for the NHS be ring-fenced? The idea is not a new one, but a leading economist is today making the case to put an end to the "famine and plenty" cycle of health service funding by doing exactly that.

In an article in the BMJ, Richard Layard, professor emeritus of economics at the London School of Economics, argues that the National Insurance system should be overhauled and converted into a German-style "designated National Health Insurance, all of which went to health".

The NHS would remain free at the point of delivery, but funded by a rate of contributions matched against the Government's five-year planned health expenditure. As in other nations, the funding pot for health should also cover social care, adds Prof Layard - but that means spending much more than we do already.

He writes: "Unfortunately, current National Insurance contributions are not enough to finance even the existing NHS, let alone social care. So we would need to increase contributions, partially offset by cuts in other forms of taxation. Extra contributions could come from requiring contributions from employees over 60, and higher contribution rates, especially from better paid employees."

The case is countered by John Appleby, chief economist at healthcare think tank, the Nuffield Trust, who argued that ring-fencing "gets the tax-spend issue back to front": public spending must be flexible, not fixed.

And so the debate goes on.

The NHS will be 70 next year, and the question of how to keep it sustainable for the next 70 years is one of the biggest questions facing us as a nation.

Since the credit crunch in 2008, funding for the NHS has fallen in real terms every year. Spiralling staff and drugs costs mean NHS inflation far exceeds the standard gauges of consumer or retail price indexes. Claims of "increased" or "record" funding (by both the Westminster and Holyrood Governments) do not mean much if it is constantly outpaced by rising costs and burgeoning demand from an ageing and increasingly obese population.

In the UK, we spend 8.5 per cent of our GDP on health and 12 per cent on social care compared to 11 and 21 per cent respectively by both France and Germany, so surely something has to give?

The tricky question is how we go about increasing that spend. If not health insurance, increased taxation is one option. But how much - and is it really a vote winner? Most would probably support the wealthiest paying more, but would a basic rate taxpayer be happy to pay 25 or 30 per cent instead in exchange for a "free" NHS?

Rationing is an alternative. The argument goes that you can increase funding for priorities such as cancer drugs and acute care by asking patients pay for more minor elective procedures, such as cataracts surgery or haemorrhoid removal. But how do you decide what is "minor" - or prevent financial incentives overriding clinical motives.

The NHS is too important to be a political football, but too expensive not to become one.

Personally, I want to hear from the real experts: the doctors, nurses, health professionals and patients. Professional bodies have been reluctant to nail their colours to the mast and say how we should fund the NHS in future. That needs to change.