In early January Boston Mayor Martin J. Walsh filed a lawsuit against the Massachusetts Gaming Commission asking that they stop Wynn Everett Casino from going forward unless the people of Boston were allowed to vote the project up or down in a binding referendum election. The commission approved the $1.6 billion development across the river in Everett last September.

An amended lawsuit was filed this week requesting a judge to prohibit the regulators from any future action on the resort. Mayor Walsh announced the amended complaint on Thursday.

“The commission’s award of the license was the product of a corrupt process to favor Wynn,” the amended complain states. “Their conduct has irreparably tainted the gaming licensing process, and has demonstrated that they are unwilling and unable to fulfill their legal obligations to serve as independent regulators.”

The commission fired back with accusations of a “personal assault” by Walsh on commission members and said the suit was, “wholly unproductive” in solving complex policy issues.

“The commission made each license award based solely on a thoughtful, objective and exhaustive evaluation of each gaming proposal,” spokesperson Elaine Driscoll said.

The original lawsuit filed in January was on the heels of separate legal challenges to Wynn Resorts’ license filed by the cities of Somerville and Revere, the sites of failed casino bids. Joining the cities in the previous lawsuits are the Mohegan Sun who lost out to Wynn for the region’s license – and a labor union which represents workers at Suffolk Downs in Revere – another losing suitor in the bid for the third license of four to be awarded.

Penn national Gaming was given a license for a slots parlor in Plainville, and MGM took the first casino resort license for their $800 million Springfield resort. The final license will be awarded to Mass Gaming and Entertainment for a casino in Brockton, or KG Urban Enterprises who are looking to build a Foxwoods casino on the New Bedford waterfront. Last week Crossroads Massachusetts LLC announced they were withdrawing their bid for a casino in Somerset.