LONDON - Google faces a London trial over an estimated 920-milion-pound ($1.1 billion) damages claim after a court authorised a lawsuit that alleges the Alphabet-owned tech giant overcharged 19.5 million customers for app store purchases.

The class action, which was certified by the Competition Appeal Tribunal on Monday, alleges Google abused its dominant position by charging up to 30% commission on popular apps on its Play Store, including Roblox, Candy Crush Saga and Tinder since October 2015.

A detailed judgment has yet to be published, a spokesperson for the claimant group said on Tuesday.

Google did not immediately reply to requests for comment.

Regulators, rivals and consumer champions are trying to curb Big Tech, filing lawsuits across the globe against the likes of Google and rival Apple over alleged anti-competitive behaviour. The European Union alone has fined Google more than 8 billion euros ($8.2 billion) in recent years over anti-trust practices.

The latest British case against Google, which is not expected to come to trial before 2024, is brought by Liz Coll, a former digital policy manager at the non-profit Citizens Advice service. She is being advised by law firm Hausfeld.

Coll alleges in the lawsuit that the Play Store commission is unlawful and unjustifiable, breaching European and British competition laws, and that Google is abusing its dominant position at the expense of British Android smartphone and tablet users.

Google generated $11.2 billion in revenue from its mobile app store in 2019, a court filing unsealed last year showed.

($1 = 0.8336 pounds)

($1 = 0.9760 euros)

(Reporting by Kirstin Ridley; Editing by Emelia Sithole-Matarise)