East Windsor residents opposed to the casino the Mashantucket Pequot and Mohegan tribes have agreed to build in their town are pursuing a process that could lead — belatedly — to a townwide referendum on the matter.

The tribes, seeking to protect their southeastern Connecticut casinos from the competitive threat posed by MGM Springfield, a $950 million resort casino scheduled to open next year in Massachusetts, settled months ago on East Windsor as the prospective site of a $300 million “satellite” facility.

In March, the leaders of the tribes and East Windsor’s first selectman, Robert Maynard, signed an agreement for the development of a casino on the site of a former Showcase Cinemas off Exit 45 of Interstate 91. At the time, and since then, some town residents have said the agreement should have been put to a referendum.

The East Windsor casino project hinges on the state legislature’s approval of enabling legislation that would grant the tribes the exclusive right to develop a third Connecticut casino. Competing bills under consideration in Hartford would instead establish a competitive-bidding process among casino operators.

Maynard confirmed Tuesday that the East Windsor town clerk received a petition late last week seeking a town meeting on a proposed ordinance that would regulate gaming facilities in town, how such facilities would operate and where they could be located. He said the signatures — 20 were required — have been certified but that the town attorney has yet to render an opinion on whether the proposed ordinance is valid.

“We’re looking at the ordinance; town counsel is reviewing it,” Maynard said. “We anticipated something like this might occur.”

If a special town meeting is called, the petitioning group is prepared to submit at least 200 signatures on petitions seeking to have the meeting adjourned to a referendum, according to Brianna Stronk, an East Windsor resident involved in the effort.

Stronk said 336 signatures have been gathered.

It’s unclear whether the proposed ordinance will pass muster with town counsel, or whether it has a chance of reversing the agreement that’s in place.

“We’re not sure it can go into effect because the agreement has already been signed,” Stronk said Tuesday of the proposed ordinance.

She said she would have preferred a referendum on whether the agreement between the town and the tribes should be rescinded.

The Coalition Against Casino Expansion in Connecticut, a group of mostly faith-based organizations, joined East Windsor residents in pushing for a referendum. Stronk said an East Windsor businessman presented the proposed ordinance to the coalition. The businessman has remained anonymous.

A provision in the proposed ordinance would scuttle the proposed casino because of its location.

“The licensed premises of a gambling facility or like business shall be at least two thousand five hundred feet from the property line of any property on which (a) residential treatment facility operated by the State of Connecticut is located,” the provision reads.

The former Showcase Cinemas site is within 2,500 feet of the Albert J. Solnit Children's Center, a state-run psychiatric residential treatment facility for adolescent males between the ages of 13 and 17. 

Even if the effort fails, or if a referendum is defeated, Stronk said, it’s important for residents to send a message.

“Residents deserve to be heard,” said Michele Mudrick, a spokeswoman for the coalition. “A lot of the legislation that’s been proposed is in favor of a referendum in any town where a casino would be. If we do have a referendum, I’m sure the General Assembly would take notice (of the outcome).”

While the petitioning group had hoped a referendum question on the proposed casino ordinance could be added to the agenda of the town’s annual budget referendum, which is May 9, that seems unlikely, according to Maynard, the first selectman.

“We’d like people to vote only on the budget and not some ancillary thing,” he said.

b.hallenbeck@theday.com