Sprint commended the Justice Department for suing to block AT&T’s proposed merger with T-Mobile, angering AT&T and raising questions about its future plans.Sprint, which has long opposed the pending $39 billion merger, rejoiced at this setback for its rival and top U.S. wireless provider AT&T.“The DoJ today delivered a decisive victory for consumers, competition and our country,” said Vonya B. McCann, senior vice president of government affairs for Sprint. “Sprint applauds the DoJ for conducting a careful and thorough review and for reaching a just decision — one which will ensure that consumers continue to reap the benefits of a competitive U.S. wireless industry.”The lawsuit likely made Sprint’s CEO Dan Hesse happy, as he has campaigned against the merger since this spring, making the case to lawmakers in Washington that a marriage between AT&T and T-Mobile would ruin the wireless industry. Hesse says the takeover would quash competition, besides acknowledging his company would sink to a distant last place in a post-merger world.While Sprint relished the taste of victory, AT&T yesterday soured at the DoJ’s suit and requested an expedited hearing on the merger. AT&T likely desires a faster hearing to reiterate its case before anyone else files a suit against its proposed marriage to T-Mobile.“We are surprised and disappointed by today’s action,” said AT&T’s senior vice president and general counsel Wayne Watts. “The DoJ has the burden of proving alleged anti-competitive affects and we intend to vigorously contest this matter in court.”He then enumerated the supposed benefits of the merger, citing increased spectrum, greatly expanded 4G LTE broadband service and tens of thousands of American jobs.“Contrary to AT&T’s assertions, today’s action will preserve American jobs, strengthen the American economy, and encourage innovation,” according to Sprint’s McCann, refuting AT&T’s claims.The DoJ yesterday sided with Sprint when it sued to prevent the AT&T/T-Mobile merger, warning of dire consequences should these two tie the knot. Specifically, the DoJ alleged a merger would decrease competition by eliminating T-Mobile as an independent competitor in the mobile market.The FCC has the final authority over the merger, and the agency’s review of the deal will likely be affected by the DoJ filing.“By filing suit today, the Department of Justice has concluded that AT&T’s acquisition of T-Mobile would substantially lessen competition in violation of the antitrust laws,” said FCC chairman Julius Genachowski.In other words, the FCC plans to take the DoJ’s complaint seriously in its assessment of the merger, which could bode ill for AT&T.Whatever the FCC decides, if it sticks with the traditional route, AT&T will likely not be overjoyed. According to an unnamed FCC official, the commission has never approved any mergers that the DoJ challenged.This post originally appeared at Mobiledia.