Sprint’s clearly no fan of the pending AT&T/T-mobile merger: in recent memory, they’ve pledged to complain to Congress, commissioned a study to illustrate how awful it would be, and cheered on the Department of Justice as they filed an antitrust suit to halt the proceedings.

Now, instead of just sniping from the sidelines, Sprint is taking a more active stance on situation. Their first step: filing their own lawsuit against AT&T, T-Mobile, and Deutsche Telekom.

Empowered by the DoJ’s legal maneuvering, Sprint’s recently filed suit claims that the potential AT&T/T-Mobile merger violates Section 7 of the Clayton Antitrust Act. Sprint alleges that if allowed, the merger would (among other things) raise prices, stifle innovation, further cement Verizon and AT&T’s power, and harm Sprint and other smaller carriers.

Susan Z. Haller, Sprint’s VP of Litigation, has stated that they are “are continuing that advocacy on behalf of consumers and competition” — a laudable goal, but one that reeks of PR tweaking all the way through. While they make some serious points about potential effects of a merger on the marketplace, Sprint’s really fighting for survival.

They’re playing their cards pretty well here: the lawsuit was a well-calculated, well-timed move, and you can bet Sprint will continue to ride their consumer-friendly high horse as long as they can. Sprint is going to keep playing up their hero angle, hoping that no matter how this all ends, potential customers will remember their role in all this.