A federal lawsuit challenging the state’s right to reserve a casino license in southeastern Massachusetts for an Indian tribe will go forward without any involvement from the Vineyard.

In a decision issued yesterday, U.S. District Judge Nathaniel Gorton denied attempts by the Wampanoag Tribe of Gay Head (Aquinnah), the town of Aquinnah and the Aquinnah Gay Head Community Association to intervene in a case brought by a private casino developer against Gov. Deval Patrick and the Massachusetts Gaming Commission.

The judge also denied the Wampanoag tribe of Mashpee’s effort to intervene in the case, but left open the possibility that it could get involved later.

The ruling is the latest chapter in a complicated bid by the Aquinnah tribe to stay in the running for the right to operate a gaming facility in Massachusetts after the state opted to negotiate with the Mashpee tribe instead. The state, along with the town of Aquinnah and the taxpayers association, contend that the Aquinnah tribe waived its right to conduct gaming on tribal lands when it signed a settlement agreement with the town in 1985. In the underlying case, commercial developer K.G. Urban Enterprises of New York claims the 2011 state Gaming Act is unconstitutional by setting aside one of three state casino licenses for federally recognized Indian tribes. The developer contends that because the preference is “racial-based” it violates the Constitution’s equal protection clause.

The Mashpee tribe has signed a second compact with the state and hopes to begin building a casino in Taunton as early as next year. An earlier compact between the state and the Mashpee Wampanoags was rejected by the Bureau of Indian Affairs which said it allowed the state to keep too much of the gaming revenues. The state legislature is now considering the second compact.

Both the Mashpee and the Vineyard Wampanoag tribes moved to intervene in the KG Urban lawsuit to support the state’s right to give preference to Indian tribes. The town of Aquinnah and the Aquinnah Gay Head Community Association, which opposes the efforts of the Vineyard tribe to build a casino, then moved to intervene to protect their position.

In the 22-page decision, Judge Gorton said what the tribes hoped to accomplish by intervening could be adequately represented by the state Attorney General. Because the Aquinnah tribe is not involved in active negotiations for a compact, its interests were too remote to merit status as an intervenor in the case, the judge found. Since the Aquinnah tribe was not allowed in, there was no reason for the town or the homeowners group to intervene, he said.

Cheryl Andrews-Maltais, chairman of the Vineyard tribe, said in an email sent Friday to the Gazette that the tribe was disappointed with the decision, and  disagrees that the state can fairly represent the tribe's interest, especially because it does not recognize the tribe's right to offer gaming on its existing trust lands.

"We will be consulting with our legal team on our next steps," she said.

In a statement, the chairman of the Mashpee Wampanoag tribe said the ruling confirmed that the KG Urban case would have no bearing on the validity of the compact between the state and the Mashpee tribe.

“This is very positive for the tribe,” said chairman Cedric Cromwell. “Our concern was that KG Urban not be allowed to use its lawsuit to in any way affect our rights as a sovereign nation or to interfere with the incredible progress we are making to finalize a deal with the state and have our land taken into trust.”

Aquinnah town counsel Ronald H. Rappaport praised the outcome. “We’re pleased with the decision because it means we don’t have to spend town resources on extensive and costly litigation,” Mr. Rappaport said.