The latest round of talks between the MTA and LIRR unions ended after less than four hours Tuesday with both sides holding their positions, and the MTA's chief looking to Congress for a solution.

At the conclusion of the bargaining session, Metropolitan Transportation Authority spokesman Adam Lisberg announced that agency chairman Thomas Prendergast will head to Washington, D.C., Wednesday to talk to congressional members about whether they intend to intervene in the four-year-long labor dispute, which could culminate in a July 20 strike.

"Nothing is going to happen at the table here clearly, based on what happened today, and that's why we're going to Congress," Lisberg said outside the Times Square law offices where the talks took place. No new meetings have been scheduled.

Lisberg declined to detail what went on during the negotiation session, which was overseen by members of the National Mediation Board and included a half-dozen Long Island Rail Road union leaders, but indicated both sides stuck with their most recent settlement offers.

"The proposal that the unions have put forward has not changed in six months," Lisberg said. "The offer we made two weeks ago is our standing offer."

The MTA also released a letter sent by Prendergast to members of Congress Tuesday seeking "clarification on what role Congress intends to play" in the event of a strike.

Before the talks, Anthony Simon, lead union negotiator, said he was optimistic even as the MTA "has not respected the process."

That process culminated with two separate, independent mediation boards appointed by the White House -- both calling for a six-year contract with net raises totaling 17 percent, first-time employee health care contributions and no changes to work rules or pensions.

The MTA is pushing for a leaner contract, with 17 percent raises spread over seven years and several concessions affecting future workers. Without a settlement, LIRR workers could legally walk off their jobs in less than two weeks.

"The MTA is trying to put the strike on us. The strike is not on us," Simon said. "The MTA, when they decide they're going to come to the table with a reasonable offer, and we will counter, like we always have."

Further extinguishing hope to avert a strike, Gov. Andrew M. Cuomo indicated Monday that he would not intervene to help broker a deal.

"I think the governor can tell the MTA what to do, and tell them it's time to prevent a strike," Simon said, noting that even after reaching a pact, both sides would likely be back at the table in 18 months negotiating their next contract. Simon said the MTA should "live to fight another day."

Arriving at the negotiations, Christopher Natale, head of the Brotherhood of Railroad Signalmen, said he was not optimistic for a good result at Tuesday's talks.

"After what the governor stated, it's not looking very good," Natale said. "He's got the power to stop this."

Ricardo Sanchez, general chairman of the International Brotherhood of Electrical Workers, said Tuesday's talks should start with the ball in the MTA's court, because the last round of negotiations ended with the MTA not responding to a union counteroffer -- the details of which labor officials have not disclosed. "They're modest raises," he said. "No one's getting rich here."