British advertisers filed a collective action lawsuit against Google seeking £3 billion ($4 billion) in compensation.
The claim alleges Google abused its dominance in the online display advertising market since 2015.
Claimants argue Google favored its own services, forcing advertisers to pay higher prices for less effective ads.
This case follows similar antitrust challenges against Google’s advertising technology in the UK, Europe, and the United States.
The company currently faces a separate UK overcharging claim and a significant European Union antitrust fine.
These legal actions target Google's primary revenue source amid increasing global regulatory pressure.