NHS trusts that have hospital building contracts with private firms may be forced to cut services, a report has said.

Private finance initiative contracts offer limited scope for savings, so they may have to be found elsewhere, according to a study from the National Audit Office.

The NHS has to find efficiency savings of up to £20bn as part of wider cost-cutting aims.

Today’s report said: “It is likely that trusts will be expected to make efficiency savings over the next few years, but their ability to make savings from their PFI contracts is very limited.

“Because trusts pay an index-linked fixed sum, it is difficult for them to make savings without cutting back on services.

“Contractors who secure economies of scale through managing multiple PFI contracts are rarely required to share these efficiency gains with trusts.

“Trusts need to ensure that any decision to reduce services is informed of the long-term consequences to costs and the impact on patients.”

The report, which looked at how PFI contracts operate once a building is open, said the cost and performance of services like cleaning, laundry and portering in PFI hospitals are similar to those provided in non-PFI hospitals.

While catering is on average slightly cheaper in PFI hospitals, hospitals with PFI buildings spend more on maintenance to keep the buildings to a specified high standard.

Amyas Morse, head of the NAO, said: “In the longer term, trusts will need support from the Department of Health to ensure that the current good performance is maintained, that efficiencies are sought and that an appropriate share of benefit comes back to the public sector.”

There are more than 70 PFI hospitals in England, costing around £900m a year and with a capital value of more than £6bn.