Google will head to trial in September as US regulators intensify efforts to dismantle the tech giant’s dominance over digital advertising.

A US federal judge has set a September 22 court date following their earlier ruling that Google operates two illegal monopolies in the digital ad market, harming publishers and consumers.

The US Department of Justice (DOJ) is pushing for a breakup of Google’s ad tech empire, specifically calling for the removal of its publisher ad server and ad exchange businesses.

The tools, which allow publishers to manage and sell digital ad space, are at the centre of what the DOJ describes as exclusionary conduct that distorts fair competition.

Google, which intends to appeal, argues that a forced sale is legally flawed and would damage the broader ad landscape. A decision could have far-reaching effects on how advertising dollars are spent across the internet.

This legal battle is only part of a wider regulatory storm facing Google. In a separate DOJ case, the company has also been found guilty of monopolising the search market. Remedies under consideration include forcing Google to sell its Chrome browser and share search data with competitors.

At the heart of both cases is how Google uses its dominance to give its own platforms an unfair edge – an issue now extending into AI.

In court testimony last week, a Google executive confirmed the company can train its AI-powered search features using web content even when publishers have opted out of AI data training – unless they fully block Google Search via the robots.txt file. The DOJ claims this practice gives Google’s AI an unfair advantage, enabling AI-generated answers in search that undercut traffic to independent websites.

Meanwhile, Google is preparing to roll out its ‘AI Mode’ to a wider audience. Previously available only in Labs, AI Mode will soon appear as a dedicated tab in Google Search for a small percentage of U.S. users. The tool, designed to rival AI-first search platforms like Perplexity and ChatGPT, uses Google’s massive data index to provide direct AI-generated answers instead of traditional link lists.

With regulators circling and its AI practices under scrutiny, Google’s dominance across search and advertising is facing its toughest test yet.