The Wampanoag Tribe of Aquinnah is taking its pursuit of a casino license to federal court, filing a motion on Friday to intervene in an existing lawsuit that challenges the state’s 2011 casino law.
The Martha’s Vineyard-based tribe argues that the outcome of that lawsuit — filed last November by KG Urban, a company seeking to build a commercial casino in New Bedford — could deprive the Aquinnah of an opportunity to pursue a tribal casino.
“There are issues being decided in this case that will be very important to us,” said John J. Duffy, a lawyer representing the tribe. The Aquinnah argue they should be allowed to participate in the case because the tribe cannot depend on the state or KG Urban to protect its interests in court.
The Aquinnah’s effort to join the case could complicate what is already an unsettled fight for casino development rights in Southeastern Massachusetts.
KG is challenging language in the casino law that delays any bidding for a commercial resort casino in the southeast to give a federally recognized tribe the chance to make progress toward a tribal casino.
Native American tribes are entitled to pursue gambling under a 1988 federal law, the Indian Gaming Regulatory Act.
If a tribe is successful in winning federal approval for a casino in Southeastern Massachusetts, the state is not expected to license a competing commercial gambling resort in the region.
In suing the state, KG Urban is seeking the right to compete for a commercial license in the southeast.
Governor Deval Patrick in July reached a deal with another tribe, the Mashpee Wampanoag, over the terms for a tribal casino in Taunton. But there is no guarantee the Mashpee will ever be able to build a casino because the tribe still must overcome legal obstacles.
Patrick has refused to negotiate a casino deal with the Aquinnah, citing a longstanding position among state officials that the Aquinnah gave up their federal rights to host gambling because of a land settlement in the 1980s, when the tribe agreed to abide by state law on its sovereign territory.
The Aquinnah have long maintained that they have the right to pursue gambling. A 20-page brief the tribe filed on Friday begins to flesh out their argument.
The tribe says that the Indian Gaming Regulatory Act, which became law after the tribe’s land settlement, is an “implied repeal” of the restrictions that would prohibit an Aquinnah tribal casino.
In February, US District Judge Nathaniel Gorton upheld the state law and dismissed KG’s challenge.
The company appealed and the US Court of Appeals for the First Circuit in August vacated the dismissal and remanded the case back to the lower court. The case is scheduled for a status conference on Monday.
Mark Arsenault can be reached at firstname.lastname@example.org. Follow him on Twitter @bostonglobemark