Google could be forced to pay over five million iPhone users £2.7 billion in compensation as it is accused of selling their data without their consent.

A new consumer campaign called "Google You Owe Us" is launching a class action against the web giant over allegedly unlawfully harvesting the browsing histories of iPhone users without their permission.

A group of at least 5.4 million affected consumers could be owed hundreds of pounds each in compensation, according to Richard Lloyd, former Which? executive director and Government adviser, who is spearheading the action.

If successful the case would be the biggest compensation bill ever paid to British consumers over improper use of data. A claim by 5.4 million people for £500 each would result in a £2.7 bn payout for Google.

Between June 2011 and February 2012, it is alleged that Google unlawfully harvested the personal information of millions of people in the UK by bypassing the default privacy settings on the Apple iPhone. Google’s algorithms allowed them to trick people's iPhones into releasing personal data from the phone’s default browser, Safari. This has become known as the ‘Safari Workaround’.

Mr Lloyd and legal experts believe this was against the law because it breached Section 4 of the Data Protection Act 1998. Under Section 13 of the Act individuals can claim compensation for breaches of the Act.