Google is being taken to court, accused of collecting the personal data of millions of users, in the first mass legal action of its kind in the UK. It focuses on allegations that Google unlawfully harvested information from 5.4 million UK user by bypassing privacy settings on their Apple iPhones handsets.

The group taking action - Google You Own Us - is led by former director of consumer magazine Which, Richard Lloyd. He estimates the users could get as much as "several hundred pounds each".

The case centres on how Google used cookies - small pieces of computer text that are used to collect information from devices in order to deliver targeted ads. The complaint is that for several months in 2011 and 2012 Google placed ad-tracking cookies on the devices of Safari users which is set by default to block such cookies. The Safari workaround, as it became know, affected a variety of devices but the UK case will focus on iPhone users.

Mr Lloyd told the BBC: "In all my years speaking up for consumers, I've rarely seen such a massive abuse of trust where so many people have no way to seek redress on their own." He added: "Through this action, we will send a strong message to Google and other tech giants in Silicon Valley that we're not afraid to flight back." Mr Lloyd said Google had told him that he must "come to California" if he wanted to pursue legal action against the firm. "It is disappointing that they are trying to hide behind procedural and jurisdictional issues rather than being held to account for their actions," he said. He added:"At the moment there is a sense that Google and similar tech giants from Silicon Valley are behaving as if they are above the law, that they can't be held to account in the courts in this country."

A Google spokesman said: "This is not new - we have defended similar cases before. We don't believe it has any merit and we will contest it."

Those affected do not have to pay any legal fees or contact any lawyers as they will automatically be part of the claim, unless they wish to opt out. The case is being supported by law firm Mishcon de Reya, which specialises in large-scale litigation.

In a statement, Google You Own US wrote: "We believe that Google took millions of iPhone users' personal information illegally in 2011 and 2012. 'Google did this by bypassing default privacy settings on the iPhone's Safari browser. This has been called 'the Safari Workaround.' The workaround tracked internet browsing history, which Google then used to sell a targeted advertising service. Google makes huge amounts of money from selling targeted advertising. In 2016, they earned $80 billion (£59.4 billion )from advertising alone.

The case is reported to start next year and is thought to be the first of its kind in the UK.