Commuters will not be able to get online whilst on London's underground system any time soon, after Transport for London (TfL) have held off on plans to provide 3G coverage on the tube.

Transport bosses had trialled the service on the Waterloo and City line for a six-month period last year, during which time the technology involved was seen to work smoothly.

However, the viability of rolling out access across the extensive tube network in the capital has been deemed too costly for the time being.

A spokesperson for TfL commented: "London Underground tendered for a trial of mobile phones on the Waterloo and City line but the market has yet to provide us with a credible proposal for enabling mobile phone use on the tube.

"While it is technically possible to deploy mobile phone and data wireless solutions on the deep level underground tunnels and stations, the unique nature and environment of the tube mean that project costs would be prohibitively high at this time."

The emergency services currently operate a system which allows communications in the underground network.