Hawaii State Teachers Association leaders have stirred up "unnecessary drama" in the organization’s ongoing labor dispute, alienated other unions and made arguments that threaten collective-bargaining rights, the University of Hawaii faculty union told its members.

The biting message, delivered in an email Thursday night, comes as HSTA prepares to begin proceedings in a "prohibited practice" complaint against the state for its decision to impose a "last, best and final" offer on Hawaii’s 12,500 public school teachers on July 1.

The University of Hawaii Professional Assembly said nearly 90 people, including representatives from UHPA and other public-sector unions, have been subpoenaed to testify in the Hawaii Labor Relations Board hearings set to begin next week.

UHPA is participating as an "intervener" in HSTA’s case — something it requested to make its own legal arguments on issues potentially relevant to future negotiations.

J.N. Musto, UHPA executive director, told the Star-Advertiser on Friday the email to members was aimed at highlighting the "rather difficult position" UHPA finds itself in. "We are the sister union of HSTA. We have a great amount of aloha for teachers," he said.

HSTA President Wil Okabe did not respond to several calls for comment.

In its email, UHPA said it was growing concerned about legal actions filed by the teachers union, "including attacks on the character of other union leaders." The email said HSTA’s arguments could "jeopardize the rights of public sector unions, including the right to strike," and have "alienated virtually everyone."

HSTA has argued it cannot strike with pending complaints before the labor board, something UHPA vehemently disagrees with. HSTA has also said other public-sector unions have gotten better deals and favored treatment — at the expense of schoolteachers.

"The notion of a conspiracy is an insult," the UHPA email said. "It is troubling that Hawaii’s teachers are the ones who must endure the circuitous and destructive route HSTA leadership has chosen. These tactics create unnecessary drama; not a settled contract."

HSTA filed a complaint with the labor relations board after the state’s decision to unilaterally implement a contract offer with wage reductions totaling 5 percent and higher health insurance premiums, which increased by as much as 110 percent for some teachers.

In addition to the primary complaint, the teachers union has gone before HLRB to request relief from the terms of the "last, best" offer (a motion HLRB is still taking under advisement) and to raise other concerns, including on whether a letter the governor sent to HLRB’s chairman constituted improper communication with the quasi-judicial board.

HLRB said Thursday the letter, in which the state agreed to mediation under certain terms, was permissible. The teachers union argued the letter attempted to influence the board, and is seeking a separate opinion on the issue from the state Ethics Commission.