Eye surgery patients in Oxfordshire are failing to use a controversial, privately-run mobile theatre, which cost the NHS £700,000.

Managers claim the mobile unit, run by South African firm Netcare, has yet to be "embedded", and patients need to be made aware of it.

It was launched in April to operate on people with cataracts, but during the first five months has only treated 29 per cent of the patients it was expected to care for on visits to Bicester and Wantage.

Critics believe that, because the mobile theatre was paid for in advance, it is now wasting scarce funds while the NHS in the county faces a £35m deficit.

The Government said in 2003 that the unit help to reduce a backlog of patients waiting more than three months for cataract oper- ations.

But non-executive NHS directors in Oxfordshire were concerned they would end up paying for a service that would not be used, because patients were already treated efficiently by the Oxford Eye Hospital, at the Radcliffe Infirmary.

Despite their fears, Cherwell Vale and South West Oxfordshire Primary Care Trusts signed up, on the understanding that Thames Valley Health Authority would underwrite the bill if patients failed to use it.

Between April and August, 107 patients were assessed by Netcare, even though it was contracted to see 381, and only 94 underwent operations, although the firm was paid to treat 307.

Oxford West and Abingdon MP Dr Evan Harris said: "It's a complete waste of money, because the NHS is now paying for inactivity at a time when the Oxfordshire health system is facing cuts across the board."

Vale of White Horse councillor Monica Lovatt said: "Most of these patients are elderly. They usually have other disabilities and want to go to a hospital they know and feel comfortable in."

Andrew Murphy, associate director of access for Oxford Radcliffe Hospitals, which runs the Eye Hospital, admitted the trust did not want Netcare's contract to be renewed, but said that if the service was not used, funding would be lost.

He said: "The uptake hasn't been too good, because people don't want to use the Netcare service. There has been capacity wastage.

"We have a choice of either allowing money to be wasted, where staff sit around doing nothing, when they could be treating patients, or using this resource so finances are spent in the best possible way."

Emma Tidy, Cherwell Vale PCT's director of commissioning and modernisation, said activity was increasing.

She said: "We're continuing to work with GPs, optometrists and the public to raise awareness of the new facilities, to ensure activity continues to rise."