In her weekly internet address, EU telecoms commissioner Viviane Reding warned: "Do you want to turn the internet into a jungle? This could happen if we cannot control the use of our information online. There is an undeniable risk that privacy is being lost to the brave new world of intrusive technologies."

The commission's legal action, which could result in the government being dragged before the European court of justice, centres on the handling of controversial online advertising technology developed by UK-based Phorm which has been tested by BT in the UK and cleared by the authorities.

That technology enables internet service providers (ISPs) to track what a user does on the internet to create a list of their interests which can be used to show them more relevant adverts on websites they subsequently visit. While heralded by ISPs and media companies as a way of making more money from internet advertising, a market dominated in the UK by Google, it has been widely criticised by privacy campaigners and the web's creator, Sir Tim Berners-Lee, as unjustifiable online snooping.