In a major legal move, 18 states, including Minnesota, have banded together to file an antitrust suit against online retail giant Amazon. The Federal Trade Commission (FTC) and 17 state attorneys general joined forces on Tuesday to accuse Amazon of illegally leveraging its dominant market position to keep prices high and limit competition.

The case follows unsuccessful negotiations between Amazon and the FTC last month, during which the company refused to budge on its business practices. According to Politico and the Wall Street Journal, the complaint centers on Amazon’s alleged actions to prevent lower prices on competing websites and force merchants to use its own logistics and advertising services.

At its core, the FTC’s case is focused on proving that Amazon’s practices violate antitrust laws. The action marks a significant step in the ongoing scrutiny of tech giants such as Amazon, who have faced increasing scrutiny over their market dominance and potential impact on competition.

In addition to Minnesota, seventeen other states have joined the lawsuit: Connecticut, Delaware, Maine, Maryland, Massachusetts, Michigan, New Jersey, New Hampshire, New Mexico, Nevada, New York, Oklahoma, Oregon, Pennsylvania, Rhode Island, and Wisconsin.