Google is being sued in the high court for as much as £3.2bn for the alleged “clandestine tracking and collation” of personal information from 4.4 million iPhone users in the UK.

The collective action is being led by former Which? director Richard Lloyd over claims Google bypassed the privacy settings of Apple’s Safari browser on iPhones between August 2011 and February 2012 in order to divide people into categories for advertisers.

At the opening of an expected two-day hearing in London on Monday, lawyers for Lloyd’s campaign group Google You Owe Us told the court information collected by Google included race, physical and mental heath, political leanings, sexuality, social class, financial, shopping habits and location data.

Hugh Tomlinson QC, representing Lloyd, said information was then “aggregated” and users were put into groups such as “football lovers” or “current affairs enthusiasts” for the targeting of advertising.

Tomlinson said the data was gathered through “clandestine tracking and collation” of browsing on the iPhone, known as the “Safari Workaround” – an activity he said was exposed by a PhD researcher in 2012. Tomlinson said Google has already paid $39.5m to settle claims in the US relating to the practice. Google was fined $22.5m for the practice by the US Federal Trade Commission in 2012 and forced to pay $17m to 37 US states.

Speaking ahead of the hearing, Lloyd said: “I believe that what Google did was quite simply against the law.

“Their actions have affected millions in England and Wales and we’ll be asking the judge to ensure they are held to account in our courts.”

The campaign group hopes to win at least £1bn in compensation for an estimated 4.4 million iPhone users. Court filings show Google You Owe Us could be seeking as much as £3.2bn, meaning claimants could receive £750 per individual if successful.

Google contends the type of “representative action” being brought against it by Lloyd is unsuitable and should not go ahead. The company’s lawyers said there is no suggestion the Safari Workaround resulted in any information being disclosed to third parties.

They also said it is not possible to identify those who may have been affected and the claim has no prospect of success.

Anthony White QC, for Google, said the purpose of Lloyd’s claim was to “pursue a campaign for accountability and retribution” against the company, rather than seek compensation for affected individuals.

He said: “The court should not permit a single person to co-opt the data protection rights of millions of individuals for the purpose of advancing a personal ‘campaign’ agenda and should not allow them to place the onus on individuals who do not wish to be associated with that campaign to take positive steps to actively disassociate themselves from it.”

Tom Price, communications director for Google UK said: “The privacy and security of our users is extremely important to us. This case relates to events that took place over six years ago and that we addressed at the time.

“We believe it has no merit and should be dismissed. We’ve filed evidence in support of that view and look forward to making our case in Court.”