More than two years before a casino in Springfield is slated to open, a coalition of Connecticut legislators, the state's two federally recognized Indian tribes and union leaders announced Tuesday they are backing a bill that would allow up to three new, smaller casinos to help combat gambling competition from neighboring states.

“Massachusetts has declared economic war on us and we’re going to fight back," said State Senate Majority Leader Bob Duff, a Democrat representing Norwalk.

The casinos would be jointly run by both of the state's native American tribes off their respective reservations. Potential future facilities could be located in Hartford or Fairfield. The state senate leaders said the initiative is a way to protect jobs in Connecticut.

“Just as we would work hard to protect any other industry in our state, it is important for us to protect this industry," said State Senate President Martin Looney, a Democrat from New Haven.

The tribes are particularly interested in opening a facility along the Interstate 91 corridor. MGM Resorts International plans to open an $800 million casino in nearby Springfield, Massachusetts by 2017, providing direct competition to Connecticut facilities.

With a new hotel at Mohegan sun set to be complete next year, tribe officials say the market for casinos is becoming competitive like any other industry.

Kevin Brown, chairman of the Mohegan Tribe, said he hopes a facility can be built sooner in Connecticut to fend off competition from that casino, which plans to draw heavily from the Hartford region.

“I think, honestly, the word is equilibrium. The market in the northeast is reaching its equilibrium and the question is simply, which part of that equilibrium stake do we want to take into the state of Connecticut? And if we just sit back. We’ll lose," said Mohegan Tribe Chairman Kevin Brown.

State Sen. Catherine Osten, a Democrat whose district includes the Mohegan Sun and Foxwoods Resort Casinos, said concerns about losing jobs prompted the unprecedented push to open at least one jointly operated, satellite gambling facility.

"We will not stand aside and let other states — New York, Massachusetts or Rhode Island — take jobs away from Connecticut," Osten said at a Capitol news conference.

While final details still need to be ironed out, the bill would allow the tribes to open three stand-alone casinos. They are expected to have mostly slot machines with some table games, but no hotels or theaters.

"We are confident that as a mixed-use urban revitalization project our innovative downtown design, tested marketing plan and strong brand will make MGM Springfield a unique destination resort casino in the Northeast," MGM Springfield spokesperson Carole Brennan said in a statement Tuesday. "We look forward to a March 24 groundbreaking and officially kicking off our construction phase."

State Sen. Timothy Larson, co-chairman of the General Assembly's Public Safety Committee, said the bill would require a certain amount of revenue from the casinos be set aside to help combat problem gambling. It also would require a public hearing in the host town and additional revenue for the state.

A public hearing is tentatively planned on March 17 to discuss the legislation, which is being pushed strongly by the Senate Democratic caucus.

The two tribes currently have exclusive rights to offer casino-style gambling in Connecticut under an agreement that provides the state with 25 percent of the slot-machine revenues from Mohegan Sun and Foxwoods.

Connecticut lawmakers are particularly interested in protecting the continued flow of Indian gaming payments to the state's coffers, even though they've dropped off in recent years. A major portion of the money is divided up among the state's 169 cities and towns.

"This is still a significant revenue source for our state and our cities," said Looney.

Fiscal year 2013 marked the first time in 15 years the state collected more revenue from the lottery than its share of slot machine money from the two tribal casinos.

Data compiled by the Department of Consumer Protection's gaming division showed the Connecticut Lottery Corp. transferred $312.1 million to the state's General Fund for fiscal year 2013. The account is the main spending account for state government.

In comparison, Foxwoods and Mohegan Sun transferred a total of nearly $296.4 million to the fund. That figure dropped to $279.9 million in fiscal year 2014 and was projected to drop further to $267.5 this fiscal year. Democratic Gov. Dannel Malloy's budget projects the state's share will further decline, to a low of $254.3 million in fiscal year 2017.

The high point for revenue to the state from both tribes was in 2007. That's when they contributed a total of nearly $430.5 million — $229 million from Mohegan Sun and nearly $201.4 million from Foxwoods.

Since then, the contributions have steadily declined. The drop has been blamed on the recession and gambling competition from other states.

Connecticut still relies more on the nearly $10 billion it collects annually from the state's personal income tax than the approximately $600 million it collects in total gambling revenues from the lottery, Indian gaming payments, off-track betting and charitable games to balance its approximate $20 billion annual budget.