Firms are bidding for fewer PFI projects because of costs and delays, says a National Audit Office report.

Before 2004, 85% of PFI projects attracted three or more developed bid,s but the figure is now 67%, says the audit office. One in three projects reaching financial close between 2004 and 2006 attracted two bidders.

In an analysis of 49 projects, the report found the average length of time for tendering had not improved in the past six years. Between 2004 and 2006 it lasted 34 months – the same as 2000 to 2003.

The audit office has called for target times of 18 to 24 months on tendering, with extensions for large or complicated schemes. It advocates setting up an annual league table of procurement times.

Richard Saxon, an RIBA council member who sits on the PFI working group, said that these suggestions would not solve the problem of delays.

He said: “It’s more important to take out complexity than set time limits.

“Projects shouldn’t go to the market until the brief and the concept design are worked out.”