The California Coalition Against Gambling Expansion will file a lawsuit in Sacramento Superior Court within two weeks seeking an injunction to shut down the state's Mega Millions multistate lotto as unconstitutional, it said Thursday.

If successful in the lawsuit, it could cost the California Lottery plenty. Possible lawsuits by the other 11 states in the game, lost startup costs, a dent in the lottery's sales-fostering integrity and other fallout could total tens of millions of dollars.

Adopting a new tactic, anti-gambling coalition officials also said that it now wants Californians, not Gov. Arnold Schwarzenegger and the Legislature, to make changes to the 1984 voter-approved Lottery Act that would allow California to participate in games outside state borders.

"I can't believe how flippant they're acting, when they are a public agency. They're not a private corporation," said Fred Jones, the anti-gambling group's attorney. "They're playing with public revenues and saying, 'We may or may not have the authority, but it's an appropriate business risk.'"

"We anticipate filing suit within the next two weeks,"Jones said. "And we anticipate that we will win the injunction."

The governor's office referred calls to the lottery, where officials were not immediately available. For days, the Schwarzenegger administration has deferred queries to acting lottery director Chon Gutierrez.

On Tuesday, Gutierrez testified at an emergency legislative hearing to delay the launch of Mega Millions and afterward said in an interview that some are calling the kickoff "a gamble." But he said he prefers to call it "a matter of managing risk" and that it ultimately could bring schools an additional $170 million annually.

The anti-gambling group expects legal maneuvering from the state, including perhaps trying to move it to federal court because it involves 11 other states. "It's classic David and Goliath," Jones said.

Sen. Dean Florez, a Bakersfield-area Democrat who convened the legislative hearing, said he believes the lottery was trying to "save face" by launching the Mega Millions game despite legal questions.

At the hearing, state Sen. Dave Cox, R-Sacramento, said he backed the lottery's move and thought it to be legal.

In the game, players pay $1 to pick six numbers from 1 to 52 to match those drawn twice weekly. Bets in California are pooled with the existing Mega Millions states of New York, Texas, Massachusetts, Michigan, Ohio, Maryland, Georgia, Illinois, New Jersey, Virginia and Washington.

Though the game boasts jackpots of perhaps up to $500 million, the odds of winning Mega Millions is about 1-in-175 million; of winning in California's Super Lotto Plus, 1-in-41 million.