The acrimonious relationship between Mayor Martin J. Walsh and casino mogul Steve Wynn took a turn for the worse Friday, when what the mayor described as a peace offering from Wynn by day’s end touched off a new round of squabbling.
The latest dispute between the City of Boston and the Las Vegas billionaire broke out after Walsh announced that Wynn had called him this week to offer “hundreds of millions” of dollars to persuade him to end the city’s legal battle over the Wynn’s planned $1.7 billion casino in Everett.
But later in the day, Wynn said he had never made such an offer during their brief telephone conversation on Wednesday.
The “he said, he said” episode is likely to add mistrust in a relationship of two men that is already marked with suspicion. Walsh has led an aggressive legal effort to derail Wynn’s casino, contending his license was awarded as a result of a “corrupt process,” and that the proposal would unduly burden Boston residents.
On Friday, Walsh said on WGBH radio that Wynn had offered a “nine-figure” sum to resolve their dispute. The mayor said he did not make a commitment to the casino executive.
“He just threw a figure at me,” Walsh said in recounting his discussion with Wynn in an interview on Friday. “I think it was just kind of a conversation piece.”
But Wynn said no such discussion occurred.
“Mr. Wynn made no offer to Mayor Walsh on the call and a ‘nine-figure’ number was never mentioned except in the context of Mr. Wynn telling Mayor Walsh that he has already spent $300 million in Massachusetts pursuing a gaming license and planning a casino,” Michael Weaver, a spokesman for Wynn, said in a statement. Later on Friday, Wynn called Walsh to tell the mayor he was mistaken, according to Weaver.
Bonnie McGilpin, a spokeswoman for Walsh, said: “The mayor stands by his comments.”
Both sides do agree on one thing: Walsh and Wynn expressed a desire to meet for further discussion in person in Boston after Labor Day.
Last month Wynn threatened to sue Walsh for defamation unless he apologizes for the “false statements and untrue innuendo” contained in subpoenas and other documents recently filed as part of the city’s lawsuit against the state Gaming Commission.
And earlier this week, in a conference call with investors, Wynn expressed frustration doing business in Massachusetts, saying “the welcome mat seemed to be out. We just haven’t found the welcome mat yet, but I’m the eternal optimist, and . . . hoping it’ll feel good when they stop hitting us.”
Walsh said he tried to clear the air during their phone conversation on Wednesday.
“It’s not personal,” the mayor said he told Wynn. “Even though it sounds like it’s personal.”
Wynn has previously offered lucrative concessions to get the city’s support for his casino. The money would help offset the negative effects of a casino on Boston’s border, including increased traffic at already-congested Sullivan Square in Charlestown. He’s also offered to subsidize the Orange Line to add extra trains during certain hours of the day.
In the interview with the Globe, Walsh said Wynn has offered no specifics beyond a figure. The two sides have sharply differed over the accounting of the money in Wynn’s offers.
“Putting numbers out there is one step,” Walsh said. “The second step is how and where and when the numbers come from. That is important.”
Walsh first mentioned Wynn’s offer on WGBH radio Friday.
Walsh has pursued an aggressive legal strategy to block the casino by filing a lawsuit that has entangled Wynn’s efforts to build what would be a 24-floor, curved glass tower next to the Mystic River on a 33-acre site in Everett. The lawsuit asks a judge to overturn the state Gaming Commission’s award last year of a casino license to Wynn, over a rival proposal from Suffolk Downs and its partner, Mohegan Sun.
In the lawsuit, Walsh argues that the commission should have allowed Boston’s Charlestown neighborhood to vote on whether to accept a casino because much of the traffic it generates would travel through Sullivan Square.
“You have to make sure as you move forward in this process that the people of Charlestown have a voice in this,” Walsh said Friday. “For them, it’s not necessarily about money. It’s about infrastructure, fixing up the infrastructure around there. The traffic is going to be very difficult for the residents of that neighborhood and for Boston.”
Before he can break ground, Wynn still needs a crucial environmental permit from the state. The request is before Environmental Affairs Secretary Matthew Beaton, who is expected to make a decision in late August.
The city, meanwhile, is due back in court on Sept. 22 for a hearing on the lawsuit before Judge Janet Sanders.
On July 9, Sanders ordered the city to put on hold, at least temporarily, subpoenas to interview potential witnesses and obtain documents as part of its ongoing investigation into the awarding of the casino license.
Sean P. Murphy can be reached at firstname.lastname@example.org.
Follow him on Twitter @spmurphyboston.
Shirley Leung is a Globe columnist. She can be reached at email@example.com. Follow her on Twitter @leung.