Between June 2011 and February 2012, Google bypassed the browser’s anti-tracking protections to collect browsing information from users. It has already paid tens of millions to settle the resulting suits in the U.S., and now it faces a type of class action in the U.K.

This is the first time someone has launched a “representative action” in the U.K. in a case involving data protection abuses. The suit is being organized by Richard Lloyd, a former Downing Street advisor who also led consumer association Which? from 2011 to 2016. His action is backed to the tune of £15.5 million by litigation-funder Therium.

Lloyd, who has set up a group called Google You Owe Us, is suing on behalf of all iPhone users who were in England and Wales during the affected time period. To qualify for a payout if he wins, people have to have used Safari during the period with the default security settings, and not opted out of Google’s tracking within Google’s own systems. They also have to have been resident in England and Wales on 31 May this year.

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Anyone who meets the criteria is automatically included in Lloyd’s suit, although if he wins they must register to collect their cash. Lloyd reckons around 5.4 million people could claim £200 ($269) each, which would mean a bill for Google (GOOGL) in excess of £1 billion.

Google, meanwhile, said it has “defended similar cases before,” doesn’t believe the case has any merit, and will contest it.

Privacy advocates have indeed already sued Google over the matter in the U.K. The case of Vidal Hall v Google was much smaller in scale, involving three individuals, and it resulted in a confidential settlement. However, the Court of Appeal said at the time that the facts of the case merited a full trial.