The intensification of warring words between Mayor Bloomberg and the president of the transit union, Roger Toussaint, means both sides have dug in for a protracted strike.

The drama comes to a head today when Mr. Toussaint appears in Brooklyn Supreme Court, where Judge Theodore Jones, who levied a $1 million a day fine against the union Tuesday, will decide whether to send the union leader to jail. Judge Jones said yesterday that jail time was a “distinct possibility” for Mr. Toussaint and his top two deputies for violating an injunction barring the union’s leaders from inciting or authorizing a strike.

Though both sides met in Midtown Manhattan with a mediator, Richard Curreri, the director of conciliation for the Public Employment Relations Board, most of the talking was carried out at press conferences aimed at winning a public relations war that has escalated tensions.

Amid the heightened rhetoric, however, Mr. Toussaint created a possible opening for a resolution when he said a contract could be at hand if the Metropolitan Transportation Authority took the issue of pensions off the table. Leaders from other municipal unions spoke publicly for the need for a public forum to address ways unions and government could work together to bring down pension costs.

“Provided that the pension issue comes off the table, that would be a basis for us to go back to work,” Mr. Toussaint said at a late afternoon press conference yesterday.

But the MTA chairman, Peter Kalikow, called that demand “outrageous,” and said the point is “rapidly approaching” where bargaining with the union would be “futile.”

Mayor Bloomberg appeared resolute in his position that the union’s 33,700 members return to work before negotiations continue, once again lashing out at the union’s leadership for calling the illegal strike that is now in its third day. Mr. Bloomberg, who described the traffic yesterday as “chaos on the streets,” said the strike was crippling businesses, especially retail stores. Mr. Bloomberg increased the force of his rhetoric, calling the strike “illegal” “selfish” and “unconscionable.”

“I don’t know how you’d explain to your kids that if you break the law, you get a better deal than if you’re honest,” the mayor said.

Governor Pataki hardened his tone to match the mayor’s, echoing Mr. Bloomberg’s position that negotiations should not resume until workers returned to the table.

“You can’t walk and talk at the same time,” Mr. Pataki said. “I think it’s just a horrible breach of trust with the people of New York.

Meanwhile, the MTA began airing television commercials. One of the commercials features the president of New York City Transit, Lawrence Reuter, urging workers to cross the picket line and come back to work. Mr. Reuter has said in reports that about 1,000 workers have refused to strike. Mr. Toussaint challenged that claim, which he said was aimed at damaging the resolve of striking workers who are being docked two days pay for every day on the job.

Mr. Toussaint defended what he called the mischaracterizations in the press and rebutted comments made over the past 48 hours, in particular Mr. Bloomberg’s view on Tuesday that the union leadership had “thuggishly turned their backs on New York City, and disgraced the noble concept of public service.”

Mr. Toussaint, speaking before re porters at the Grand Hyatt hotel, returned the volley.

“The thugs are not on this side of the podium,” he said. “We are not thugs. We are not selfish. We are not greedy.”

Mr. Toussaint, who earns a salary of $101,990, according to the union’s filings with the federal labor department, sought to portray the strike, which is illegal under the state’s Taylor law, as a form of civil disobedience. To make his point, he invoked the legacy of the civil rights movement.

“We have pointed out that there is a higher calling than the law and that is justice and equality,” Mr. Toussaint said. “Had Rosa Parks answered the call of the law instead of the higher call of justice many of us who are driving buses today would still be in the back of the bus.”

Pensions remain at the heart of the impasse. The MTA, as part of its final offer Monday night, asked new employees to pay 6% of their wages toward their pensions after dropping its demand that new workers retire at age 62 instead of the current age of 55.

Mr. Toussaint, whose union filed a complaint with the Public Employment Relations Board Sunday attempting to force the MTA to take pension issue off the table, painted the issue as one of historic significance that could set a precedent for all municipal unions. Mr. Toussaint said the 6% contribution the MTA is asking of new workers would save it about $20 million over the life of the three year contract, a pittance for the authority.

The demand, he said, suggests the MTA had simply wanted to establish a precedent that would later be used as a tool for “whipsawing” other municipal unions into giving new workers an inferior pension package.

But the MTA says that sharply understates the savings involved. A spokesman said the contribution would save $160 million in the first ten years, and that the savings would then increase to $80 million a year.

Shortly after Mr. Toussaint addressed reporters, labor leaders from several municipal unions- including Randi Weingarten of the United Federation of Teachers; Stephen Cassidy, president of the Uniformed Firefighters Association, Gregory Floyd of Local 237 of the Teamsters, among others – showed support for the striking union. Labor leaders used the moment to argue for weakening the state’s Taylor law.

Mr. Cassidy, who described the prohibition in the state’s Taylor law against striking as “an automatic checkmate” against unions, also said the law gave government no incentive to complete contracts on time.

Union leaders retaliated at Mr. Bloomberg who praised the city’s unions for not striking even though some unions had been working for many years without a contract.

“Many of us are very frustrated that it takes us months and months to get our management to the table to negotiate in good faith,” Ms. Weingarten said, adding that her union has urged new legislation that would give negotiators six months after a contract expires to find a resolution. She said the governor vetoed the legislation.

Ms. Weingarten, who called discussion of the pension issue illegal, said any attempt by governments to address the rising cost of pensions should be discussed jointly between labor leaders and government leaders and away from the pressures of a negotiating table.

“Why is one union being singled out here?” she asked.

The MTA has dedicated $450 million of its $1 billion surplus to stem the rising costs of its pensions. MTA officials have repeatedly said that it must begin to address the rising costs, especially since it faces an $800 million deficit beginning in 2008.