Google is facing a potential 5 billion-pound ($6.62 billion) collective action lawsuit in the U.K. that claims it abused its dominance and overcharged companies for search advertising services.

The claim filed Wednesday–brought by British competition law academic Or Brook represented by law firm Geradin Partners–argues that Alphabet-owned Google abused its dominant position in the digital economy to exclude competitors from the general search and search advertising markets, allowing it to charge higher prices for search ads.