Report on Metronet collapse to arrive late as authors are split on who takes the blame

The National Audit Office (NAO) is to release its report on Metronet, the failed London Underground engineering group, by Easter – up to four months behind schedule.

Metronet, the private-sector consortium that was contracted to maintain and renew two-thirds of the Tube, went into administration in July 2007. It is understood the report's authors are divided over who was at fault for the collapse. The consortium behind the company, which included Balfour Beatty and Atkins, is blamed by some, while others feel that London Underground, headed by Tim O'Toole, did not let the contract particularly well. A source said: "Discussions in the drafting are trying to take the view on how much the collapse was to do with Metronet and the London Underground."

An NAO spokesman said: "We are hoping to get the report out by the Easter parliamentary recess. This is an authoritative account and that does take time to get together."