The early day motion, tabled by Conservative MP Robert Halfon, has won the support of MPs from all three main parties.

The MPs highlight concerns that “privacy is gradually being eroded by private companies using the internet to obtain personal data and selling it for commercial gain”, pointing in particular to WPP’s recent claim to have created the world’s largest database of internet user profiles, covering half a billion people, for its new Xaxis business. WPP has said that the information, which has been brought together from various businesses in its GroupM and WPP Digital groups, is anonymous.

Secret monitoring of internet users, Halfon says, is already a “huge issue”, and existing legislation and regulation through the Information Commissioner’s Office (ICO) have not been sufficient to deal with it.

The ICO has recently experienced for itself the difficulties of protecting privacy in today’s online world – it saw a 90% drop in the number of tracked visits to its website after it started asking visitors for explicit permission to place a cookie – as will soon be required of all sites in line with new European rules.