The case could have big implications for other states as they seek to rein in rising pension costs.

A top state lawmaker joined the treasurer on Wednesday in opposing Gov. Chafee's call for negotiations with labor unions seeking to overturn sweeping changes to the state's retirement system.

House Speaker Gordon Fox said it wouldn't be appropriate for him to negotiate legislation that's already been signed into law, and he said the unions' legal challenge to the pension overhaul will be decided by the courts. Fox's opposition to changing the law could hamper Chafee's desire to hammer out a deal with unions, as any compromise would have to be approved by the General Assembly.

"The time to negotiate was during the 30 hours of public hearings that were conducted by the legislature," said Fox, D-Providence. "We always anticipated that there would be a legal challenge to this."

Chafee, an independent, has said he wants to pursue settlement talks to end the closely watched and high-stakes legal fight over the 2011 pension law, which raised retirement ages, suspended pension increases and altered benefits for thousands of retired and active teachers and government workers.

The changes were designed to save an estimated $4 billion over the next 20 years.

Chafee was in Washington on Wednesday attending a National Governors Association meeting, but he issued a statement saying that while he has confidence in the state's case, the outcome is uncertain. He said it's "prudent" to consider a settlement while the lawsuit goes forward. He said he is disappointed that other state leaders oppose settlement talks.

"Some have said that now is not the time for negotiation," Chafee said. "I disagree. The state has leverage only so long as there is still uncertainty as to the outcome of this case."

Chafee met Tuesday with Bob Walsh, executive director of the National Education Association Rhode Island, and George Nee, president of the AFL-CIO. Walsh said specifics weren't discussed but Chafee expressed interest in striking a compromise.

"We're right where we want to be with the governor," Walsh said of the hour-long discussion. "It was a good first date."

Walsh said he's hopeful lawmakers could take up changes to the law after they convene in January.

Treasurer Gina Raimondo on Wednesday stressed that lawmakers passed the law overwhelmingly following months of public hearings that included input from public workers and retirees. Raimondo, a Democrat and the main architect of the pension law, said the state owes it to taxpayers to let the judicial process continue.

"It is not the time for closed-door meetings," Raimondo said in a statement. "This is not a time for politics. … It's now the job of the judicial branch to evaluate the legislation passed by the General Assembly, and we should let it do its work."

An influential business-backed organization, EngageRI, created to lobby for the pension law, also weighed in on Wednesday, saying in a statement that its members were "saddened" to hear Chafee was willing to negotiate the law.

A hearing on the state's motion to dismiss the unions' legal challenge is scheduled for Friday.