Transport for London (TfL) has made free Wifi available in over 40 stations on the underground network in an effort to keep passengers informed about service news and events during the 2012 London Olympic Games.

However, with just over three weeks to go, the Wifi provision falls short of the 80 stations promised earlier in March.

The service is provided by Virgin Media and is available to Tube passengers in the ticket halls, escalators and platforms. Users will be connected within trains, while they are at the stations, but there is no wifi service while in transit.

Users need to register an email address to connect to the service.

According to TfL, the service will be used by 100,000 passengers and has already demonstrated it can handle one million Tweets, Facebook posts, emails and web pages delivered in one week.

Passengers can get wifi connectivity at the following stations:

Green Park
Kings Cross St Pancras
Oxford Circus
Warren Street
Chancery Lane
St James’s Park
Tower Hill
Hyde Park Corner
Euston Square
Paddington on the Circle, District and Bakerloo lines.
Covent Garden
High Street Kensington
Leicester Square
Liverpool Street
Old Street
Bethnal Green
Canada Water
Canary Wharf
Elephant & Castle
Goodge Street
Marble Arch
Regents Park
West Ham
Heathrow T1-3
North Greenwich
Mile End

TfL has promised to keep the service freely available to Tube passengers after the Games has finished and extend the number of stations connected to 120 by the end of the year.

This roll-out will coincide with the deployment of limited free Wifi at 56 overground stations throughout the capital, slated for the second half of the year.

Users there will be allotted 60 minutes free internet access each day at each station once they go through a one-time registration process.