The partnership of Foxwoods Resort Casino and Mohegan Sun Thursday turned up the heat in their campaign to open a third Connecticut casino, launching a digital attack ad against their biggest foe in the fight, MGM Resorts International.

MMCT Venture — a partnership of the Mashantucket Pequot and Mohegan tribes — focused the video on clips of MGM executives talking about how they are going to aggressively seek out gambling dollars from Connecticut. The money would be spent at MGM's $950 million casino and entertainment complex now under construction in Springfield.

"We are ideally positioned to go into Hartford and attack," MGM President William Hornbuckle says, in one portion of the video.

The video was launched a day after the tribes and workers from both casinos met with legislators at the Capitol and Gov. Dannel P. Malloy questioned MGM's motives for opposing MMCT's plans to establish a "satellite" casino in East Windsor.

Malloy said East Windsor threatens to siphon off gambling revenue that would otherwise have gone to Springfield.

"That's why they're in the building," Malloy said. "Let's not argue that they're the defenders of commerce. They're not. They want their exclusive piece of the pie, based on the casino in Springfield."

The video pushes the merits of MMCT's plans for East Windsor that would directly compete with Springfield, the intent of one casino expansion bill. It is central to a strategy for preserving Connecticut's gaming industry, including money spent at the tribes' casinos, jobs tied to the industry and the revenue the state draws from monthly from slots at Foxwoods and Mohegan Sun.

MGM has aggressively opposed MMCT's plan, pushing for opposing legislation that would allow a competitive bidding process. The process would allow more casino operators to bid alongside the tribes, opening up the potential for more revenue for the state. MGM argues southwestern Connecticut would be more lucrative, one MGM would be interested in pursuing because it taps into the attractive New York market.

In addition to MGM, at least two other casino operators — Caesars Entertainment and Pinnacle Entertainment — have met with legislators.

MGM also took a swing at MMCT Thursday, questioning a tax-fixing agreement for East Windsor that holds steady property taxes for the first five years of casino operation.

East Windsor First Selectman Robert Maynard said the development agreement pegs the fair market value of the casino property at $250 million, with taxes of $5.5 million, for the first five years, plus an additional $3 million each year.

The fixing deal, which needed to be written into the bill favoring h was requested by MMCT so its investors would know the cost of taxes in the early years of operation, Maynard said.

After five years, the property would be subject to the normal cycle of assessment.