Sen. Elizabeth Warren (D-Mass.) on Wednesday introduced legislation aimed at stopping large, anticompetitive mergers that would also give antitrust regulators more authorities to stop deals without going to court.

Warren said the Prohibiting Anticompetitive Mergers Act of 2022 (S. 3847) would have prohibited Lockheed Martin‘s [LMT] proposed $4.4 billion acquisition of rocket maker Aerojet Rocketdyne [AJRD], which was ultimately blocked by the Federal Trade Commission (FTC) due to anticompetitive concerns.

The bill was introduced in the House by Rep. Mondaire Jones (D-N.Y.) and includes another eight senators and 11 representatives as co-sponsors, all of whom are Democrats.

The bill would make illegal deals valued at over $5 billion, or result in market shares of over 33 percent for sellers or 25 percent for employers, or that result in highly concentrated markets as defined by the Department of Justice in 1992 guidelines for mergers.

The FTC in late January said it would file a lawsuit in federal court to prevent the proposed deal for Aerojet Rocketdyne, a move that led Lockheed Martin to terminate the deal several weeks later.

The FTC said it opposed the deal because it would eliminate the last independent supplier of critical missile propulsion systems, reducing competition, stifling innovation and increasing prices for government customers. Northrop Grumman [NOC], through its 2018 acquisition of the former Orbital ATK, left Aerojet as the only independent U.S. supplier of missile and rocket propulsion technology.

“For the last five decades, big companies have had almost free reign over our economy, squashing competitors, growing bigger and bigger, and abusing their market power to price gouge consumers and crush workers and small businesses,” Warren said in a statement. “This unconstitutional behavior has to stop. My new bill with Rep. Jones would restore our country’s anti-monopoly tradition by banning the biggest, most anticompetitive mergers and giving the DoJ and FTC stronger tools to enforce our antitrust laws and restore real competition in our markets.”

In addition to setting illegal merger criteria, the proposed legislation would give antitrust agencies more teeth, allowing them to stop mergers without seeking a court order, and would require agencies to reject prohibited mergers. The bill also takes aim at private equity acquisitions by prohibiting the “roll-up” of companies that ends up consolidating industries.

A fact sheet accompanying the release of the bill says that relevant state attorney generals and agencies would also be involved in merger reviews, such as including the Defense Department for large deals, as part of a “whole of government” review. DoD is already typically involved in merger reviews.

The bill would also allow the government to unwind anticompetitive deals that have already been completed during the 21st Century, requiring a breakup of a merger that resulted in more than 50 percent market share, or materially harmed competition, workers, consumers or small businesses. It would also allow state attorney generals to sue to break up harmful mergers.