As the Massachusetts legislature moves closer to opening up casino gambling in the commonwealth, the Wampanoag Tribe of Gay Head (Aquinnah) suddenly vaulted into the spotlight this week, its leaders claiming that they have a better plan than their sister tribe in Mashpee for building a Fall River casino.

In an appearance outside the state house in Boston on Wednesday, Naomi Carney, head of the Wampanoag Gaming Corporation, and Cheryl Andrews-Maltais, chairman of the Aquinnah tribe, unveiled a rendering for a gambling resort on 240 acres off Interstate 195 in Fall River. They also issued some tough threats, declaring that if they are unable to win a license for their project in Fall River, that they intend to build a casino on property the tribe owns on the Vineyard.

It’s all academic still, since the legislature has not yet enacted a law to allow gambling. But there is one in progress: the house has approved a bill that would permit three casinos to be licensed in the state — two licenses would be issued through a public bidding process and one would go to a recognized Indian tribe. The Aquinnah and Mashpee Wampanoags are the only federally recognized tribes in Massachusetts. The state senate is due to vote on the bill before the legislature adjourns for its summer recess in August. Gov. Deval Patrick supports casino gambling, and The Boston Globe is reporting that the bill has a strong likelihood of passing due to the pressures of the economic recession. The senate held a public hearing on the bill on Wednesday this week that lasted for several hours and saw testimony from a wide array of people, including union leaders, who strongly support casinos, and politicians and academics who oppose it. Opponents were noticeably in the minority.

Following the hearing, Ms. Carney and Mrs. Andrews-Maltais held a press conference outside the state house to talk about their rival casino plan.

Ms. Carney is a resident of New Bedford who served one term on the New Bedford City Council. Ms. Andrews-Maltais has been chairman of the Aquinnah tribe for two and a half years. She lives in Edgartown. The two women are sisters.

At this juncture the odds are well stacked against the Aquinnah tribe, even though they are by far the senior tribe, having achieved formal recognition in 1987, while the Mashpee Wampanoags received theirs three years ago.

Nevertheless the Mashpee Wampanoags, who are larger in number and at least outwardly better organized, already have a signed agreement with Fall River mayor William Flanagan for their casino resort plan on a 300-acre city property they bought last month that was previously planned as a biotech park. And they have a financial backer: a Malaysian firm that has built casinos around the world.

By contrast the Aquinnah Wamapnoags have no financial backer that they can name, and they do not have the support of the Fall River mayor, who told The Boston Globe this week that their plan is problematic, not least because it would be built on the edge of a major wetland. “The Mashpee proposal is light years ahead of the Aquinnah proposal,” Mayor Flanagan told The Boston Globe on Wednesday.

The Massachusetts Secretary of State’s office said yesterday that there are 16 Wampanoag corporations listed with the secretary of state, but none under the name Wampanoag Gaming Corporation.

Ms. Carney and Ms. Andrews-Maltais could not be reached for comment yesterday.

The Aquinnah tribe has a history of unsuccessful attempts to enter the lucrative world of gaming that goes back for nearly two decades.

In 1993, six years after the tribe had won federal recognition, it began to pursue casino plans, lining up investors and hiring lobbyists to work the state house in an attempt to pass legislation. In 1994 the tribe began a partnership with Carnival Hotels and Casinos and won support from then-Gov. William Weld to build a $175 million casino in New Bedford that the tribe claimed would create thousands of jobs and bring in millions of dollars in revenue for the state.

That plan, and others that followed, foundered on Beacon Hill. And for a time casino gambling faded from view.

Three years ago it came back into focus when the Aquinnah Wampanoags announced they had formed a partnership with Seneca Nation, a New York state tribe that operates three successful casinos.

There was no mention of Seneca Nation in the announcement by the Wampanoags this week. Their Boston attorney, Richard Bennett, told The Boston Globe that the tribe could not disclose the names of its financial backers.

And the claim by the Wampanoags that they could build a casino on the Vineyard also appears dubious at this juncture, in part because of a 2004 state Supreme Judicial Court decision that decided a crucial question about the tribe’s status as a sovereign nation. The state’s highest court ruled that the Wampanoags had agreed to abide by state and local zoning laws for land use projects when they signed a settlement agreement in 1986. The settlement agreement, which was years in the making, led to federal recognition for the tribe. Because of the supreme court decision, the tribe is bound to follow all pertinent regulatory review — including by the Martha’s Vineyard Commission — for land use projects.

The tribe opted not to appeal the decision to the U.S. Supreme Court; therefore the ruling is now permanent law.

In a statement that preceded the senate hearing this week, Gregory Bialecki, the top economic development aide to Governor Patrick, also cast doubt on the Aquinnah tribe plan and gave his own vote of confidence for the Mashpee Wampanoags. “It’s been our view, and it’s the view of others as well, that the Mashpee Wampanoags are the one group that have a serious potential ability to establish their tribal gaming rights in Massachusetts,” Mr. Bialecki said.

By JULIA WELLS