The city of San Jose, Calif., on Tuesday escalated a bitter baseball turf war, voting to file suit against Major League Baseball in an attempt to finally bring the Athletics franchise to town.

The sticking point is that the San Francisco Giants claim territorial rights to the whole region — including San Jose, some 40 miles south of the Giants' stadium. Unwilling to risk losing market share to a relocated, rebranded team, the Giants have effectively blocked the A's from moving down there for years.

San Jose seeks to negate that extensive land claim, arguing that it violates state and federal laws regulating marketplace competition. In particular, the suit challenges the league's federal antitrust exemption, saying the exemption has allowed baseball to establish "unreasonable restraint on competition."

More from the San Francisco Chronicle:

"This action arises from the blatant conspiracy by Major League Baseball to prevent the Athletics Baseball Club from moving to San Jose," the suit says. "This action challenges — and seeks to remedy — defendants' violation of state laws and use of the illegal cartel that results from these agreements to eliminate competition in the playing of games in the San Francisco Bay Area." [San Francisco Chronicle]

The antitrust component of the lawsuit could potentially have deep repercussions for the league's finances. A 1922 Supreme Court ruling granted baseball its unique exemption from the Sherman Act, saying that while teams from different states competed against each other, the games themselves were intrastate events, and thus not subject to federal commerce law. That exemption has gone virtually unchallenged since the 1970s, even as the league has assumed wide control over merchandise, broadcast rights, and teams' geographic distribution.

The league could initiate a process to overrule San Francisco and move a club in on its turf. That would require a three-fourths vote from all the team's owners.

However, MLB Commissioner Bud Selig has resisted Oakland's pleas for such a vote, instead appointing a committee to study the proposed move. Selig created that committee over four years ago and nothing has ever come of it, leading San Jose to claim the league was merely avoiding the issue.

Rob Manfred, an MLB executive vice president, said in a statement Tuesday that MLB had always "acted in the best interests of our fans, our communities, and the league" when considering the A's relocation.

"The lawsuit is an unfounded attack on the fundamental structures of a professional sports league," he added. "It is regrettable that the city has resorted to litigation that has no basis in law or in fact."

Though they've been eager to get out of Oakland and into a new stadium for some time, the A's are not a part of the lawsuit themselves. A's owner Lew Wolff said in a statement that he was "not in favor of legal action or legal threats to solve business issues."

The A's currently play in a mixed-use stadium, the Coliseum, which routinely ranks as one of the worst in baseball. Days before San Jose filed its lawsuit, faulty pipes dumped sewage into the stadium, "creating a stink and pools of water," as ESPN put it, and forcing the A's to share a clubhouse for the day with the visiting Mariners.