THE Royal Blackburn Hospital will cost taxpayers an estimated £680million in interest to the private firms which funded its construction, the Lancashire Telegraph can reveal.

Despite the hospital costing £113million to build, the East Lancashire NHS Trust will spend around £1.3million a month for the building over 35 years - enough to employ 1,000 nurses a year during this time.

It has also been revealed that health bosses will pay back an estimated £180million in interest for Burnley General Hospital's Phase Five extension, which cost £30million.

The trust will therefore payback just over one billion pounds for work which cost £143million.

Critics branded the payments "horrific" and "staggering", but NHS chiefs said it was the only way to fund the work.

The figures were made public for the first time following a Freedom of Information Act request by the Lancashire Telegraph.

Building work at the hospitals across the country has been carried out under the Private Finance Initiative (PFI).

Rather than be paid for upfront by the Government, the work was financed and built by a group of bankers and builders and "mortgaged" back at a higher cost.

The Royal Blackburn was built by Consort Healthcare, which receives the monthly payments. The consortium is made up of builder Balfour Beatty and banking giant HSBC.

The £113 extention opened last July and benefited from £20million worth of new equipment.

A spokesman for Consort Healthcare said: "We believe that PFI is good value for money - the unitary charge includes a number of operational costs and services.

"These include energy, facilities management, small works requested by the trust and life cycle of the building comprising replacement, managed equipment and keeping the hospital in a good state of repair."

The cash-strapped trust only broke even for the first time since its formation in 2003 last month after a £14million savings programme which saw a reduction in the number of beds.

And the trust faces a £15.9million savings programme during this financial year.

Coun Tony Humphrys, chairman of Blackburn with Darwen Council's health and social care overview and scrutiny committee, said it the figures on the buildings' cost were "absolutely staggering".

Coun Humphrys said: "They have still got money problems and this is just adding to that.

"I am absolutely flabbergasted.

"PFI should not be used to build hospitals.

"If the Government wants to build new hospitals, which I am in favour of, then it should pay for it. Private investment should not be used in public services.

"That money could be better spent on providing services for the people. My grandchildren, generations to come will still be paying for it."

Ribble Valley MP Nigel Evans said the levels of interest were "horrific".

He said: "This is taking money away from frontline medical services.

"Now we know where all this extra money for the NHS is going."

Catalyst Healthcare built the Burnley extension. A spokesman said it was "great value for money Leader of Burnley Council, Coun Gordon Birtwistle slammed the hospital trust.

He said: "It is ridiculous the amount having to be paid back.

"They cannot afford to pay to run the hospitals that is why they are making cuts."

A trust spokesman said PFI was the only option to finance the work.

He said: "The benefits of the schemes speak for themselves. We have excellent new facilities that were delivered on time and on budget.

"It is important to emphasise that as part of the PFI agreement our PFI partners are required to maintain each building as new'.

"This means that they will make substantial reinvestment in the buildings over the course of the agreement."

A spokeswoman for the Department of Health said it was "value for money".

During the last 10 years the average rate of inflation has been 2.6 per cent.

If the rate was at two per cent then during 35 years - the agreed period of the inflation-linked repayments - the final costs for the Royal Blackburn and Burnley General would be £789million and £210million.