Connecticut’s third casino finally could get off the ground in East Windsor.

The project, stalled by the U.S. Department of the Interior’s failure to act on the Mashantucket Pequot and Mohegan tribes’ amended gaming agreements with the state, got a huge boost Thursday, when the department announced it will publish notice Friday that the Mohegans’ agreement is taking effect.

Notice that the Mashantuckets’ agreement is effective is expected to follow.

“We are pleased that the department is taking this step and we expect similar action on the Mashantucket Pequot tribal amendments in the very near future," said Andrew Doba, a spokesman for MMCT Venture, the Mashantucket-Mohegan partnership pursuing the East Windsor casino. "Our goal has never changed. We want to do right by Connecticut and to preserve the strong relationship between our tribal nations and the state."

"Today's decision is the latest step in our overall goal to preserve thousands of good paying jobs and millions in state tax revenue," he said.

Friday’s notice will appear in the Federal Register, the daily journal of the U.S. government.

U.S. Sen. Richard Blumenthal, D-Conn., who had joined other members of the Connecticut delegation in calling for an investigation of the Interior Department’s failure to act on the amendments, said the investigation that's underway should continue.

“Interior has the right results but at the wrong time,” he said in a phone interview. “It’s permitting this agreement to take effect long after it should have approved it. The delay has been deeply harmful in practical terms and remains deeply suspect for all the reasons we asked the inspector general to investigate it.”

Blumenthal, Sen. Chris Murphy, D-Conn., and Reps. John Larson, D-1st District, and Joe Courtney, D-2nd District, requested the probe in February, citing reports that MGM Resorts International had managed to persuade Interior officials to avoid acting on the tribes’ amendments. MGM Resorts, the Las Vegas-based gaming operator whose soon-to-open Springfield, Mass., casino is expected to hurt the tribes’ southeastern Connecticut casinos, Foxwoods and Mohegan Sun, got Nevada lawmakers to lobby Interior, according to news reports.

It was reported that Interior officials rejected the input of staff members who recommended the tribes’ gaming agreements be approved.

“I believe the inspector general’s investigation should continue to a conclusion and it must ... to uncover whether there was any conflict of interest or other wrongdoing," Blumenthal said. "Why did it take so long to do the right thing?”

He said the delay in the start of construction at the East Windsor casino site “has caused substantial hardship for the state and the tribes by preventing the Connecticut casinos from opening (East Windsor) prior to the MGM casino.”

“Time is an important factor,” Blumenthal said.

Gov. Dannel P. Malloy signed the law authorizing the tribes’ East Windsor casino in June 2017. The authorization was contingent on federal approval of the gaming amendments incorporating the third casino. When the Interior Department failed to act on the amendments, the state and the tribes filed a federal lawsuit seeking to compel action.

The suit, which is pending, contends that because Interior failed to act on the amendments within 45 days of their submission, the amendments, under Indian Gaming Regulatory Act regulations, should be considered "deemed approved."

In its response, Interior argues that the Mashantuckets should be dropped from the suit because their casino (Foxwoods) operates under gaming procedures prescribed by the Interior secretary rather than in accordance with a state-tribal compact, which is the case with Mohegan Sun.

Blumenthal said he expects Interior to publish the Mashantuckets’ amended agreement in the same way it's publishing the Mohegans’ amendment.

“We expect it will be the same,” he said. “We have reason to believe it will and it should be. Whatever the distinctions raised by other parties, the results should be the same.”

State Sen. Cathy Osten, D-Sprague, a staunch advocate of the tribes’ third casino plan, said she expects publication of the Mashantuckets’ amendment “very shortly.”

“This is just where we want to be,” she said. “We need to start the process of protecting jobs and revenue for Connecticut.”

Osten has advocated a legislative “fix” to eliminate the need for the tribes to secure federal approval of their amended agreements. That’s no longer necessary, she said.

b.hallenbeck@theday.com