NURSES fought to keep critical care patients alive by hand yesterday when a brand new £67m North-East hospital suffered a total power failure.

MPs last night demanded to know how the hospital, in Bishop Auckland, County Durham, could be left without power for 20 minutes.

The early morning crisis is believed to have been caused by malfunctioning electrical switching equipment.

Every hospital has a so-called uninterrupted power supply, which is meant to maintain electricity to critical machinery in the event of a power cut.

Although the hospital's back-up generator worked according to plan when the external power supply failed, officials said the switch that should have automatically reconnected the mains supply to the hospital failed to work.

With the generator off-line the hospital was plunged into darkness.

The emergency left two patients on life-support machines unable to breath.

Nurses had to manually ventilate them for 20 minutes as engineers battled to restore the electricity.

Last night, hospital boss John Saxby said an investigation had already been launched to discover what went wrong.

Mr Saxby, chief executive of County Durham and Darlington Acute Hospitals NHS Trust, said: "As with any hospital, we have plans in place to deal with situations like this and our emergency procedures were successfully implemented.

"Our staff responded immediately and no patient suffered as a result of the power failure. There were two patients on ventilators in the critical care unit.

"Again, emergency procedures were successfully implemented and the patients were ventilated by hand."

Mr Saxby said that power was restored in time to prevent any operations being cancelled.

He added: "A thorough investigation is currently under way to find out why it happened and to ensure that the problem is resolved.

"In the meantime, alterations have been made to the system to enable the generator to continue to run, in the event of a power failure, until an engineer supervises the change back to mains supply."

Mr Saxby stressed that this had been a problem with an individual component and was not a problem which had been experienced previously.

The hospital, built under the Government's controversial private finance initiative (PFI), was only opened by Prime Minister Tony Blair last summer.

Bishop Auckland MP Mr Derek Foster last night expressed concern at the incident.

"I will be making immediate arrangements to speak to the chief executive, John Saxby, and call for a full explanation," he said.

The MP for Durham North, Kevan Jones, who has been an outspoken critic of PFI hospitals, said: "This is obviously very concerning for patients, the trust needs to sort it out."

Patients from North Durham can increasingly expect to be given the choice of a referral to the Bishop Auckland hospital for non-urgent, planned surgery as part of a controversial plan to improve hospital services in County Durham.

While the new hospital was widely welcomed in the Wear Valley town, the local community has had to accept unpopular plans to downgrade the hospital's maternity unit and transfer the special care baby unit to Darlington Memorial Hospital.

The Prime Minister has hailed the new PFI-built hospital as part of the wider regeneration of the NHS under New Labour.

NHS officials are preparing the facility for a new role as the main centre for routine operations in County Durham.