The Mayor of London, Ken Livingstone, called for an "extraordinary review" of "massive" cost overruns by the consortium responsible for maintaining most of the Tube system.
Mr Livingstone denounced Metronet's "inefficiency" and formally asked the London Underground regulator to investigate.
Chris Bolt, the official arbiter of the public-private partnership (PPP) which runs the Tube infrastructure, is being asked to decide how much of the £750m overrun will be funded by taxpayers and how much by Metronet shareholders - Atkins, Balfour Beatty, Bombardier, EDF Energy and Thames Water.
In his first annual review of Metronet's performance last November, Mr Bolt said Metronet failed a key test over whether it was "economic and efficient" in its first three years and was "significantly behind schedule" in developing and maintaining stations.
Mr Livingstone, who fought the Government's imposition of the PPP structure, said his decision to invoke arbitration followed advice from Tim O'Toole, the London Underground managing director, that Metronet's performance had not improved since the arbiter's review.
The Mayor said: "It's time to get all the cards on the table and for Metronet's shareholders to stand up to their responsibilities. They need to account for their failure to perform in an economic and efficient manner to date. We also all need to understand how Metronet will improve their performance in future. The renewal of the Underground, including the full increase in capacity promised by the PPP, is vital for the future prosperity and growth of London, and consequently the UK. I will not stand for any failure to deliver this renewal, or allow the costs of Metronet's failure to perform to fall on London."
Mr O'Toole said he had made clear his frustration with Metronet's performance in the delivery of projects and in track maintenance, but had not seen "any real evidence of improvement".
If Metronet agrees to the review, it will have to provide key financial information and Mr Livingstone said he would call on the Government to take action over the 30-year contract if Metronet refused.
Mr Livingstone said that if he had the power, he would have stripped Metronet of its contract by now. He said the contract had "ripped off" Londoners.
A Metronet source said the review would be distracting: "We would rather spend our time fixing London Underground rather than pushing pieces of paper around."
In an official statement, Metronet said that the consortium was investing £8bn in the first seven-and-a-half years to renew nine of the 12 lines for which it was responsible - the biggest project of its kind in the world.Reuse content