Boston Mayor Marty Walsh is unilaterally calling off all mitigation negotiations with the two companies vying to build a casino on the city’s border until after the Massachusetts Gaming Commission rules on his request to postpone any licensing decisions until after a ballot question repealing the state gaming law is voted on in November.

The move by the city throws yet another wrench into the casino licensing process but could put Boston in an awkward negotiating position if the Gaming Commission balks at more delays.

Wynn Enterprises, which wants to build a casino in Everett, is scheduled to go to arbitration with Boston on Wednesday on a surrounding community agreement. If the commission rejects Walsh’s bid for a delay, the city could be left entering arbitration without its own proposed agreement on the table. That could possibly mean that Wynn could effectively impose its own terms by default; a surrounding community agreement would be worth millions of dollars to Boston.

A spokeswoman for the Gaming Commission said the agency’s commissioners will attempt to sort out all the issues surrounding Boston’s request and its surrounding community agreements at the Wednesday meeting.

The city’s intention to stop negotiating was communicated on Monday to Wynn and Mohegan Sun, which wants to build a casino in Revere adjacent to the Suffolk Downs racetrack. A copy of the letter, signed by Boston Corporation Counsel Eugene O’Flaherty, was also sent to the Gaming Commission.

In his letter, O’Flaherty said the city intends to argue on Wednesday on behalf of its motion to stay all proceedings until after the November election. O’Flaherty said the city considers all negotiation and arbitration deadlines with the casino developers to be suspended until the commission renders its decision.

The letter then added a final, oddly worded line that seemed to imply the city might not negotiate with the casino developers regardless of how the Gaming Commission rules. “Pending the outcome of the city’s motion, the city presently does not intend to participate in negotiation and arbitration regarding the surrounding community issue,” O’Flaherty wrote.

Efforts to reach city officials and the two casino developers were unsuccessful.

Bruce Mohl oversees the production of content and edits reports, along with carrying out his own reporting with a particular focus on transportation, energy, and climate issues. He previously worked...