The extra billions being spent on the NHS by the government may fail to deliver improvements on the ground, economists have warned.

A report by the think tank the Office for Health Economics (OHE) warns that the record increases could be swallowed up by extra pay for doctors and nurses.

It also suggests that the government may be trying to boost spending too quickly and says ministers have failed to spell out exactly where the extra money will go.

The OHE analysis is partial and crude

Department of Health spokesman

NHS spending is set to increase from �65bn this year to more than �105bn by 2005.

The increases, announced in the April Budget, are part of government efforts to bring health spending in the UK up to European levels.

Ministers say the extra money will deliver major improvements across the NHS with extra doctors and nurses, more hospital beds and shorter waiting times.

Extra beds

However, the OHE report says the NHS is not growing fast enough to be able to spend the extra money effectively.

It says that more doctors and more hospital beds are needed if patients are to receive better healthcare.

Jon Sussex, associate director of the OHE, said the NHS will be unable to cut waiting times or carry out more operations without more staff and more beds.

"Spending on the NHS is going up by an awful lot over the next few years," he told BBC News Online.

"However, the extent of the money increase is much greater than the planned increase in staff. This should be a warning light.

"It is rather difficult to get major productivity increases in the NHS - to treat more people you need more staff and more beds."

To treat more people you need more staff and more beds

Jon Sussex

Mr Sussex said the government had failed to say where it was planning to spend the extra money.

"NHS spending is going up faster than ever before but it is unclear from government spending plans where that money is going. It has been unexplained so far.

Mr Sussex said that there was a chance that the extra money could fund pay rises for NHS staff.

But he added: "We have to ask ourselves if that is really what we want or whether we actually want the money to pay for an improvement in healthcare."

Report criticised

The Department of Health criticised the report and said it was increasing capacity in the NHS.

A spokesman said: "The OHE analysis is partial and crude. It overlooks some important steps that we are taking now to increase capacity and improve quality in the future.

"These include increases in training places of 54% for doctors and 60% for nurses, new hospital facilities, more and better drugs, and a �1bn investment in information technology."

He added: "We always said it would take time to reverse decades of under-investment in the NHS.

"By building capacity and reforming service delivery, we can modernise the NHS without fuelling inflation or pouring money into a black hole."