Construction of a casino in East Windsor could begin by early fall and certainly by the end of the year leaders of the tribes that run the state's two casinos said Thursday.

Kevin Brown, chairman of the Mohegan Tribal Council, said the timetable would become clearer soon, once designs are completed and final regulatory approvals are secured, noting that the punch list that remains could be resolved "in a matter of weeks, multiple weeks."

"We're off and running," Brown said. The Mohegans and Mashantucket Pequots, the operators of Mohegan Sun and Foxwoods Resort Casino respectively, joined in a partnership to establish a casino in north central Connecticut.

Brown's comments came a day after the state legislature approved the first expansion of casino gambling in Connecticut off a Native American reservation, one of the most controversial issues in this year's regular session of the General Assembly. Gov. Dannel P. Malloy is expected to sign the legislation.

The project faces an ongoing court fight, however.

The partnership of the tribes — MMCT Venture — already faces opposition in court over the expansion from MGM and possibly others, including the Schaghticoke Tribal Nation, may follow.

Court action cannot stop construction unless there is an court-imposed injunction. And the tribes maintained their intention to begin construction even under the cloud of court action.

"We're fully committed to this project, and we've always anticipated that there would be some form of legal action in addition to the current one," Butler said.

Brown and Butler declined to speculate on what would happen if the casino was built and the courts ultimately ruled against the tribes.

The casino is aimed at diluting the competitive impact of a $950 million casino and entertainment complex in Springfield being built by MGM Resorts International.

Brown and Rodney Butler, chairman of the Mashantucket Pequot Tribal Council, said in a joint interview by phone the most important issue to get accomplished is securing approval for the expansion from the U.S. Department of Interior's Bureau of Indian Affairs.

The BIA's approval is needed because the tribes agreement with the state must be altered to reflect the new casino. The agreement, known as the compact, guarantees the state will receive 25 percent of slot machine revenue monthly in exchange for the exclusive right to operate slots in Connecticut.

The tribes needed the legislation to be adopted and now need a sign-off from Malloy's office to apply to the BIA.

Altering the compact fueled tumultuous debate during the legislative session. Those opposing the tribes being given the exclusive right to expand over argued that asking the BIA to open the compact could risk the state's 25-percent of slot revenue.

The tribes last month secured non-binding guidance from the BIA that the third casino would not affect the compact.