The U.S. Justice Department told a federal judge Alphabet's Google illegally dominated online advertising technology in seeking a second antitrust win against the company.

A federal judge will hear arguments on whether Google's advertising tech constitutes a monopoly as closing arguments begin Monday.

Google and the US government will face off in a federal court on Monday, as each side delivers its closing arguments in a case revolving around the technology giant's alleged unfair domination of online advertising.

Canada's Competition Bureau has filed an antitrust lawsuit against Google, demanding the sale of key ad tech tools and penalties for alleged anti-competitive practices, echoing similar U.S. actions.

Canada's Competition Bureau is suing Google for alleged anti-competitive conduct in its online advertising. In a statement, the country's antitrust watchdog alleged Google had illegally linked two advertising tools to maintain market supremacy and used this dominant position to distort ad auctions by preferring its own tools.

In a notice filed Thursday with Canada’s Competition Tribunal, the watchdog—known as the Competition Bureau—said it seeks to “put a decisive end to Google’s structural dominance and anticompetitive practice,

Canada’s antitrust regulator is taking Alphabet Inc.’s Google to court for alleged abuse of dominance in web advertising, adding to a mounting pile of legal challenges for the search giant.