Billions are spent on health and social services every year

The debt was calculated from a survey of all Welsh NHS Trusts, local health boards and Health Commission Wales.

Overspending has risen by nearly 10% on last year, but the bulk of the deficit is down to a few key institutions.

The final figures will be presented to the Welsh Assembly Government in the coming months.

The predicted overspend of �33.45m for the last 12 months is still only a small proportion of the overall health and social services budget of �5,114.4m.

However, there are also historical debts across the Welsh NHS of around �84m, according to Welsh Assembly Government figures.

Gwent Healthcare NHS Trust is forecasting one of the greatest overspends, with an anticipated debt of �6.5m.

One-off payments

The Welsh Ambulance Service, which has suffered a turbulent 12 months with changes at the top in management and claims of crisis, is also forecasting a �6.4m debt.

Three local health boards also fared badly, with Carmarthenshire forecasting a deficit of �4.2m, Swansea an overspend of �4.468m, and Powys predicting a deficit of �3.2m.

The overall deficit figure would have passed �40m without one-off payments made to two NHS bodies.

Health Commission Wales - which has been heavily criticised for making cuts to its services - is forecasting a break even, but only due to an additional �5m payment received from the Welsh Assembly Government.

Similarly, North East Wales NHS Trust forecasts a break even position, thanks to an additional �3.2m non-recurring payment from local health boards.

'Culture of debt'

The four main political parties have reacted to the news of the anticipated overspend, with Labour saying the culture of debt must be changed and the NHS had to live within its means.

But the Conservatives said Labour had been in charge for 10 years, and the situation was getting worse. "Today's debts are tomorrow's cuts," they said.

Plaid Cymru said they wanted to establish how much of the problem was down to underfunding, and how much was down to mismanagement. They said it had to be sorted out before nursing jobs were lost.

The Liberal Democrats said there was terrible bureaucracy in the NHS, and they wanted to co-ordinate services better.

"There is mismanagement, but throwing money at the problem isn't the answer," they said.