The 30-year deal will mean the private sector SEEBOARD Powerlink operating, maintaining, financing and renewing the tube's power distribution system.

In 1996 passengers were trapped after a power failure

London Underground's high-voltage power distribution system will be upgraded as part of the deal which involves distributing electricity supplies to each station.

At present, most of the electricity to power the Tube is generated by LU's Lots Road and Greenwich stations.

The new deal will mean the shutdown in two years of the Tube's 93-year-old Lots Road power station in Chelsea. Greenwich will be retained for emergency back-up only.

In 1996, a power failure paralysed the underground's central area, trapping thousands of people in trains in tunnels.

The deal could encourage more people to use the Tube

Deputy Prime Minister John Prescott said: "This deal is good news for Tube users and it should make the network significantly more reliable.

"Despite LU's best efforts, there have been several notable failures in recent years which have brought most, or all, of the network to a standstill for many hours, frightening and annoying those unfortunate enough to be trapped on the trains.

"By improving the reliability of the power, I hope this project will also go some way towards encouraging more people to use the Underground."