Attorneys for U.S. Interior Secretary Ryan Zinke and the Department of the Interior moved Monday for "partial dismissal" of a lawsuit seeking to compel Zinke to act on amendments to the state’s gaming compacts with the Mashantucket Pequot and Mohegan tribes.

The state and the tribes sued in November over approvals for the amendments Gov. Dannel P. Malloy signed with each of the tribes last summer. The state’s authorization of the tribes' plan to develop a third Connecticut casino in East Windsor is contingent on the Interior approvals.

In their answer to the suit, filed in federal court in Washington, D.C., attorneys for Interior claim the Mashantuckets lack standing in the matter because their Foxwoods Resort Casino operates under gaming procedures prescribed by the secretary rather than in accordance with a state-tribal compact.

The department argues the Mashantuckets should be dropped from the suit.

“Consequently, Plaintiffs’ claims that the Secretary violated IGRA (Indian Gaming Regulatory Act) by not meeting time limits for tribal-state compacts must be dismissed as to Mashantucket for lack of jurisdiction and failure to state a claim …,” the federal government says in its motion. “In addition, this Court should hold that neither the state nor Mohegan have standing to assert claims with regard to Mashantucket’s gaming procedures, nor does Mashantucket have standing to assert any claims with regard to Mohegan’s compact with the state.”

A spokesman for the tribes’ business partnership, MMCT Venture, responded Monday evening:

“While troubling, this action falls in line with a pattern of behavior by the Department of the Interior,” Andrew Doba wrote in an email. “Remember, the Tribes received two technical assistance letters from the Department in furtherance of the draft amendments and those letters never hinted at this newly raised issue. When the time came to formally approve the amendments, the Department purportedly ‘returned’ the amendments, which means the amendments are deemed approved under the Indian Gaming Regulatory Act. Instead of publishing notice of approval in the Federal Register as required by law to make the amendments effective, they’ve refused."

Federal regulations call for Interior to either approve or reject gaming-compact amendments within 45 days of their submission. If there is no action, the amendments are “deemed approved.”

Following up their lawsuit, the state and the tribes filed a request in December for a “summary judgment” in their favor. Days later, MGM Resorts International, the gaming giant building a casino in Springfield, Mass., some 12 miles from East Windsor, asked to intervene in the case on Interior’s side. Some believe lobbying on MGM’s behalf is behind Interior’s inaction on the gaming amendments.

According to Monday’s court filing, the Mashantuckets sought to negotiate a tribe-state gaming compact in the late 1980s, but the state refused. When court-ordered negotiations failed, the parties submitted their last best offers to a mediator, who selected the state’s compact. The state, however, failed to consent within 60 days, prompting the mediator to submit the compact to the Interior secretary. The secretary imposed Class III gaming procedures the Mashantuckets have been operating under ever since.

The Mohegans, owners of Mohegan Sun, operate under a gaming compact negotiated with the state.

Mohegan officials have said the tribes plan to proceed this month with demolition work at the East Windsor casino site.

“As far as our litigation is concerned, nothing has changed,” Doba said. “We're still moving forward and intend to continue our fight to save jobs and revenue. We believe the law is clear and on our side."

b.hallenbeck@theday.com