NHS failures and bad management have been blamed for the collapse of the £900m St Mary's healthcare campus in Paddington, west London, last May.

A report into the £900m scheme's failure, published by the National Audit Office, blamed the two NHS trusts and their partners for the inability to secure enough land for the project and their failure to control risks.

Costs on the scheme, which would have replaced three other hospitals, rose from £300m at the time the outline business case was presented in 2000 to £894m by the time it was abandoned in May 2005.

Costs of £15m were run up in the eight years between the project's conception and its eventual failure.

The NAO said that the three partners - Royal Brompton and Harefield NHS Trust, St Mary's NHS Trust and Imperial College - failed to identify how much land was needed before the first outline business case was presented.

The report claimed that it took two years for the partners, who were joined by Partnerships UK in 2002, to realise that they did not have enough land to build the scheme under Westminster planning policy.

They were also criticised for never appointing a single accountable officer for the project, leading to a lack of clear leadership that damaged progress on the scheme.

The partners also came under fire for their decision in 2004 not to include risk management processes in the scheme.

The report identified risks such as changes in government health policy, the introduction of payment by results for hospitals and the creation of strategic health authorities and primary care trusts.

The government was also blamed for not lending sufficient support to the partners.