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鈥橳oole said: 鈥淲e are paying a premium price for improvements, but performance to date has not been good enough.鈥�

In 2003 Metronet and Tubelines were awarded 30-year contracts, worth 拢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鈥橳oole warned that there was 鈥渘o room for slippage if we are to do our part for the 2012 Olympics.鈥�