PROVIDENCE — The Ethics Commission made a decision without a vote yesterday, holding its course toward a trial-like hearing next month on Senate President Joseph Montalbano’s alleged ethics violations and setting up a probable court battle over Montalbano’s claim that he should get a jury trial on the charges.

The lawyer for one of Montalbano’s predecessors, former Senate President William Irons, meanwhile, filed a legal memorandum in support of a similar demand for a jury trial on the ethics charges against Irons, rather than a hearing before the commission.

The demands break new legal ground, since nobody had asked before that a jury trial replace the adjudicatory hearing that the commission uses to decide cases.

Irons’ lawyer, John A. Tarantino, said in the memorandum that the ethics violations Irons is accused of are really criminal in nature, despite the fact that the Ethics Commission handles them as civil matters. Criminal charges get a jury trial.

Tarantino also argued that the violations Irons is accused of were considered criminal when the state Constitution became effective in 1843, qualifying them for a jury trial then, and that any legal action which qualified for a jury trial then, still qualifies for one now.

Although lawyers in the cases say the two jury demands raise similar — and novel — legal issues, Montalbano’s case hasn’t gotten far enough to address them.

Instead, the commission and its staff wrangled for more than an hour yesterday with Montalbano’s lawyer, Max Wistow, who accused the commission of breaking its own rules in giving notice for yesterday’s hearing. Much of the meeting was devoted to disputes over procedural issues, including whether the “demand” for a jury trial Wistow had filed was really any different than a motion. (He vigorously asserted it was.)

Commission prosecutor Dianne L. Leyden said Wistow was merely trying to delay the case and the hearing, scheduled for June 5 and 6. She opposed the jury trial demand, and said the commission doesn’t have the legal authority to hold one even if it wanted to.

The commission’s independent legal counsel, Kathleen Managhan, agreed that the state Constitution and state law don’t provide for Ethics Commission jury trials, but she said the commission can rule on whether an accused official has a right to one.

If officials accused of ethics violations were regularly tried before a judge and jury, and not the commission, it would take away the commission’s greatest power, the job of enforcing the Code of Ethics, which is given to it in the state Constitution.

After Leyden repeatedly accused Wistow of using “delaying tactics,” Wistow said that he doesn’t think it’s his job to help make the process run smoothly. “It’s not my place to make things easier for the prosecution or even for the commission,” he said. To the contrary, he said, “I have a sacred obligation to my client to make things as difficult as possible for the prosecution.”

That approach appeared to annoy some commission members. James C. Segovis objected to “this fractured use of English” and, a few minutes later, said of what went on yesterday, “It’s an abuse of our time and our process.” George Weavill Jr., another commission member, remarked that “a lot of what Mr. Wistow has raised has been smoke and mirrors.”

“I‘ve apparently antagonized two members of the commission,” Wistow said a few moments later. He said he had only been trying to assert Montalbano’s rights.

The commission took no action yesterday, with the effect that, unless it is derailed, perhaps by Wistow, the hearing on the charges against Montalbano will begin June 5. Wistow would not say exactly what his next move will be, but he said that if the Ethics Commission doesn’t grant a jury trial, he’ll appeal.

“If that doesn’t happen, we’ll end up in court,” he said. “We’re not going to leave it up to the commission.” He also promised to file a number of motions attacking the prosecution’s case.

He said he wants a jury trial for Montalbano because “his best chances are in front of a jury.”

Wistow also said he and Leyden haven’t been getting along. “We have not been able to work things out on an amicable basis,” he said.

Leyden, meanwhile, argued vigorously, and successfully, that the commission should stick to its schedule and move on to the adjudicatory hearing. At that hearing, Leyden and Wistow would present their cases to the commission, which would then decide whether Montalbano is guilty and, if he is, impose a penalty, probably a sizable fine. The commission and Montalbano could also negotiate a settlement, which would typically include a fine.

Montalbano is accused of violating the ethics code by failing to report tens of thousands of dollars in income from West Warwick for legal work associated with the Narragansett Indians’ failed casino proposal there. He’s also accused of participating in Senate votes when he had a clear conflict of interest.

Irons is accused of breaking the ethics laws by using his office for financial gain and by voting on pharmacy legislation where he had a substantial conflict of interest. The charges stemmed from Irons’ participation in the Senate Corporations Committee’s consideration of pharmacy “freedom of choice” legislation in 1999 and 2000.

The commission staff and Irons negotiated a proposed settlement, but in a highly unusual development, the commission turned down the settlement, whose terms haven’t been made public.

blandis@projo.com