Sprint announced on Tuesday that it has filed a lawsuit with a federal court in the U.S. District of Columbia in an effort to block AT&T’s planned $39 billion acquisition of T-Mobile USA from Deutsche Telekom. The suit is related to the Department of Justice’s lawsuit, which was filed on August 31st. “Sprint opposes AT&T’s proposed takeover of T-Mobile,” Sprint’s vice president of litigation Suzan Haller said. “With today’s legal action, we are continuing that advocacy on behalf of consumers and competition, and expect to contribute our expertise and resources in proving that the proposed transaction is illegal.”

Sprint argued that the merger will “harm retail consumers and corporate customers by causing higher prices and less innovation” and said it will “entrench the duopoly of AT&T and Verizon” by allowing those two carriers 90% of U.S. wireless profits and more than three quarters of the market. Sprint also said the merger would “harm Sprint and other independent wireless carriers” and would give AT&T control of backhaul, roaming and wireless spectrum. AT&T responded to the DOJ’s suit last week and said the deal is in the best interest of consumers and the “facts will prevail in court.”  Read on for the full press release from Sprint.