London Underground says private firms are slipping further behind schedule.

Private firms involved in tube Public Private Partnerships are failing to provide the improvements promised, according to a London Underground (LU) report. Two years into the scheme, repeated signal failures mean that commuters are unable to benefit from the increased number of trains that are available. LU says that not enough is progress is being made to justify the cost of the scheme.

LU managing director Tim O’Toole said: “We are paying a premium price for improvements, but performance to date has not been good enough.”

In 2003 Metronet and Tubelines were awarded 30-year contracts, worth £15 bn, to maintain the network. The LU report was particularly critical of Metronet, and said that overall delays in engineering works had risen by 35%. Mr O’Toole warned that there was “no room for slippage if we are to do our part for the 2012 Olympics.”