Outside of the infrastructure issues, first mover advantage will allow EE to gather a lot of media coverage as 4G is explained, and the mental associations built up between 4G and EE will be substantial.

FORBES: Everything Everywhere To Introduce 4G LTE To Sixteen UK Cities

Virgin Media recently announced EE and Vodafone UK as wholesale partners for its WiFi service on London Underground.

ENGADGET: PSA: Virgin Media extends London Underground WiFi again, aims for 120 stations by early 2013

Millions of EE, Vodafone and Virgin Media customers2 will be able to enjoy full WiFi access across London Underground following the deal, keeping the majority of Tube passengers connected for no extra cost3 in 2013 and beyond.

ENGADGET: PSA: Virgin Media extends London Underground WiFi again, aims for 120 stations by early 2013

The letter, which was not intended to go public, was sent to six ISPs last week, namely BT, Sky, Virgin Media, O2, EE and TalkTalk.

BBC: Technology