JOHNSTON — A lawsuit filed in Superior Court accuses Mayor Joseph M. Polisena and other town officials of a biased attempt to help builders rush the construction of FM Global's new headquarters in violation of the town’s zoning laws.

Filed by CapLease, the company that owns FM Global's current headquarters building, the suit says the local officials’ “scheme” has repeatedly blocked access to important public documents and issued building permits for the project prior to final approval by the Planning Board, which closed the normal pathways to appeal.

Both Polisena and the town’s assistant solicitor, William Conley, stood by the town’s policies yesterday and promised to respond to CapLease’s numerous allegations in court.

“We will respond to the lawsuit accordingly,” Conley said.

Said Polisena: “I’m just amazed at what length they’re going through to try to keep FM Global in their building.”

FM Global's attempts to build a new $60-million headquarters near its existing home are the focal point of CapLease’s dispute with the town. The company is trying to build headquarters and move into it before its lease with CapLease expires next summer.

The landlord’s lawyers filed the 86-page complaint in Superior Court, Providence, on Wednesday afternoon. Both parties were scheduled to meet with Judge Michael A. Silverstein on Monday, according to one of the plaintiff’s lawyers, Edward D. Pare Jr.

CapLease’s suit argues that town officials have kept the landlord from halting all construction at the site, which it should be able to do as part of the normal process for appealing Planning Board decisions. The suit seeks a court order that would freeze all construction immediately.

Town officials agreed to issue the permits prematurely, in exchange for FM Global's promise to protect the municipality from “the illegality of its own conduct,” says the suit, which cites a letter in which a FM Global lawyer promises to indemnify the town if anyone filed suit over the town’s policy of permitting construction before the official time period for filing an appeal has elapsed.

In past practice, the town has made builders wait until any appeals, or pending appeals, were resolved before giving the go-ahead for construction, says the suit.

In this case, town officials have let FM Global finish the building foundations despite CapLease’s appeals, which were filed last month and will be heard by the Zoning Board of Appeals on May 14. A stop-work order issued on April 21 allowed construction crews to backfill around the foundations.

The suit cites a scheme to “delay and hinder CapLease’s ability to obtain documents and understand the project, thus leaving the project unchallenged in any meaningful manner.”

“…it is readily apparent that the town, faced with the perceived threat that FM Global might leave town, chose at the outset to do FM Globe’s bidding in derogation of the town’s legal obligations and public trust,” says the suit.

The suit quotes Polisena’s published comments on the importance of retaining FM Global. “This isn’t a grand slam,” Polisena said last year. “It’s the World Series times 10.”

Polisena said he still hasn’t gone through the document, but he’s confident in the decisions made by planning officials and the building official and reviewed by the town’s lawyer.

He acknowledged the indemnity agreement, saying the neighbors were “on board so to speak” and he wanted to help FM Global make its construction deadlines.

“We said, sure no problem,” Polisena said.

mreynold@projo.com