Google’s advertising business has frequently been the subject of antitrust investigations from competition watchdogs across the world in a broader effort to diminish the company’s alleged dominance in the advertising technology business. Earlier this year, the US Justice Department and eight states sued the search giant, accusing it of monopolizing digital ads through anti-competitive behavior. Google allegedly abused its dominance in ad exchanges and the tools used to take part in the bidding process to cut off competitors. The lawsuit wanted Google to divest its online ad tech business, which would severely hit the company’s bottom line. The EU’s European Commission now wants the same thing, as it’s ready to formally file a “charge sheet” against Google on Wednesday.

Reuters reports that the EU seeks to push back Google’s dominance in online ads by lodging an antitrust complaint against the company. The EU’s charges have been a long time coming, with regulators launching a probe in 2021 to determine whether the company unfairly favored its online ad technology over competitors. The probe also sought to find out whether Google unfairly locked out rivals from data necessary for digital ads.

At the core of regulators’ gripe is Google’s online ad exchange, where the company serves as an intermediary between advertisers and publishers. Advertisers use the platform to buy ads, while website publishers rely on it to sell ads. In a nutshell, Google controls the technology being used to match advertisers with publishers.

In March, the EU’s antitrust regulators reportedly began preparing their statement of objections outlining the European Commission’s case, according to Politico. The outlet stated that EU officials requested nonconfidential documents from online publishers and advertisers to build their case.

The charge may make sense because Google’s ad exchange provides the search giant with unique insight into the process, thus giving it potential leverage. Nonetheless, Google has long denied its dominance in the digital ad market, and it’s expected to counter the EU’s charges once they are formally made public.