Private sector bidders for contracts worth £3bn to diagnose and treat NHS patients are being wooed with the prospect of a permanent place in England's healthcare market.

The deal was advertised in the official journal of the EU soon after Patricia Hewitt took over as health secretary at the start of Tony Blair's third term. Companies expressing an interest in bidding were sent more than 200 pages of documents setting out what would be expected of them. The confidential documents, dated September 8, show that the primary purpose of the contracts would be to help create a "sustainable" market in the provision of elective care to NHS patients and encourage competition between NHS and private providers. Some private companies will be given an opportunity to take over NHS buildings and equipment.

That appears to run counter to the pledge given by the former health secretary Alan Milburn when he first mooted the idea of private treatment centres to reduce the NHS waiting list. He insisted that the companies doing this business must not poach staff from the NHS.

The documents suggest that in Birmingham all surgical facilities at a new NHS treatment centre will be handed over to the company which wins the contract for up to 9,500 operations a year in general surgery, gynaecology, urology and other specialisms. Hamish Brown, breast cancer surgeon and chairman of the hospital's medical staff committee, said: "The consultants and staff have put an enormous amount of work and time into this project, to provide state of the art health care for what is one of the most deprived populations in the country.

"I doubt that will be a priority for the independent sector. They will be doing the easy work in a ready-made facility that would otherwise have cost them a fortune, at the same time as the hospital loses this income. It stinks."

Other contracts include plans to turn Ravenscourt Park hospital in west London from a public sector facility under Hammersmith Hospitals NHS trust into a "surgical hub" for a network of diagnostic and treatment centres throughout London north of the Thames.

Part of the New Forest Lymington hospital in Hampshire - a PFI scheme that is due to open next year - will be leased to a private company to carry out 5,000 operations a year. The prospectus for the West Midlands said: "This scheme is for the independent sector to build, create and manage an orthopaedic centre for excellence on the site of Rugby St Cross hospital." It involves "a significant volume of transferred activity and may involve secondment of existing NHS staff." Like many others the West Yorkshire scheme "involves a significant volume of transferred activity and may involve secondment of NHS staff".

Rules laid down by Mr Milburn and his successor, John Reid, to prevent the poaching of NHS staff have been eased. "Providers will only be prohibited from recruiting NHS staff in specialities facing workforce shortages." Doctors and nurses with full-time NHS contracts will also be allowed to do extra shifts in the private treatment centres, once they have fulfilled their NHS obligations.

Companies winning the contracts will be expected to provide performance bonds worth between £1.5m and £17.5m to insure the government against any of them defaulting on the contract.

Paul Miller, chairman of the BMA's consultants' committee, said: "I believe the government when it it says there is no intention of making NHS patients pay. But we are moving quickly towards a position where a lot of NHS staff will have to work for private firms, or lose their jobs. This is being done without any real debate. Ms Hewitt talks about putting new management into failing hospitals. I would not be surprised if that came from these private firms.

"We are moving quickly to a position where a lot of the NHS staff are employed by the private sector."