The president of the United Federation of Teachers, Randi Weingarten, has been grumbling about the lack of a teachers contract since May 31, 2003, when the last one ran out. Yesterday, on the two-year anniversary of the contract’s expiration, Ms. Weingarten ramped up her anti-Bloomberg rhetoric and detailed new, aggressive plans to secure a contract for her 140,000 members.

Ms. Weingarten called reporters to the union’s headquarters in Lower Manhattan to show a 30-second ad, starring three hardworking teachers, which started airing yesterday. She also announced that up to 20,000 educators, politicians, and entertainers, including Phoebe Snow, Toshi Reagon, the G.E. Smith Band, and Laura Flanders, would rally for a contract tomorrow afternoon at Madison Square Garden.

“I dislike to my core that there is a connection between politics and schools,” Ms. Weingarten said. But she said Mayor Bloomberg’s “foot-dragging” has placed the contract battle in the center of the political process. As November’s mayoral election nears, she said, it’s becoming increasingly unlikely the union will throw its support behind the mayor’s re-election.

“The teachers are really demoralized,” Ms. Weingarten said, adding that Mr. Bloomberg has “a lot to overcome” if he wants to win her union’s endorsement.

“With a record-breaking $3.3 billion surplus and rising test scores that demonstrate just how hard teachers work under conditions in which they feel totally demoralized, there is no longer any legitimate excuse for delay,” the union president said. “It’s time for the administration to roll up its sleeves, sit down at the bargaining table, and craft a deal with us that respects teacher input and pays a respectable wage.” Under the expired contract, the starting salary for teachers in the public schools is less than $40,000 a year.

Ms. Weingarten reminded reporters that during the 2001 campaign, Mr. Bloomberg chided Mayor Giuliani for not hammering out a contract with city teachers. She quoted him as having said, “If I had my druthers, I’d lock them in a room, put them on a starvation diet, or hunger strike, until they came up with a solution.”

She said she’d be willing to forgo food if it meant she could reach a fair contract, but she joked that she couldn’t go without coffee.

A spokesman for Mr. Bloomberg, Jordan Barowitz, would not directly address the idea of locking negotiators in a room. But he insisted that the mayor is more than willing to negotiate.

“We are ready to negotiate,” he said. “Unfortunately, the UFT has walked away from the bargaining table and prefers street theater and publicity stunts to bargaining.” Referring to the contract that City Hall negotiated with the union when Mr. Bloomberg won control of the school system, Mr. Barowitz said: “Negotiations is how we got teachers their largest-ever raise, and is the only way we will be able to reach another one.”

A political consultant, Norman Adler, who was director of political action and legislation for the largest municipal union for 11 years, said the UFT’s new offensive might hurt Mr. Bloomberg’s re-election prospects.

“Election time is no time to fight with people who can affect the outcome of the election,” Mr. Adler, who has been associated with Democratic causes, said. “That’s like the cardinal rule in politics. You want to have a fight with politically connected people, wait till after the election is over.”

He said the union’s refrain about fair contracts is powerful this year, since a new contract is two years overdue.

“Two years is disgraceful,” Mr. Adler said. “It’s a very long time for a union to go without a contract.”

Another political consultant, Hank Sheinkopf, also said a failure to agree with the teachers could create problems for the mayor. But he noted: “No mayor of recent memory has been defeated because he did not have labor support, because municipal unions were angry with him. It just doesn’t work that way.”

Nonetheless, according to Mr. Sheinkopf – who also has worked for Democrats – the new ads could increase negative perceptions of the mayor among some voters. He said tomorrow’s rally would “get politicians to stand in line and stand with the teachers union.”

All four of the Democrats running for mayor and one of the mayor’s Republican rivals, Thomas Ognibene, are planning to attend the Madison Square Garden rally.

In conversations with the Sun, all of the mayor’s rivals said that if they were leading the city, they would find a way to reach a pact with the teachers.

“While I’m not going to be a pushover for everything they want, but I do believe fundamentally that they deserve to be paid more,” a congressman from Queens, Anthony Weiner, said. “And I believe they fundamentally are part of the solution to one of New York’s most vexing problem. They are not the problem.”

Mr. Weiner, whose mother, Fran, taught at Brooklyn’s Midwood High School, said he thinks the reason that two years have passed with no compromise is the mayor’s management style.

“The mayor has adopted this corporate model that sees employees as liabilities instead of assets,” he said.

Mr. Ognibene, who will attend the rally with his schoolteacher-wife, Margaret, said the teachers deserve a new contract. He said if he were mayor he would tell the teachers they were entitled to a raise if they agree to give principals more control over the day-to-day operations of schools and to figure out a way to remove bad teachers from the system.

The Manhattan borough president, C. Virginia Fields, said through a spokesman, Nick Charles, “The fact that they don’t have a contract doesn’t serve the children of New York City. It’s great that Randi Weingarten is calling on the mayor and the city to come to the negotiating table, but the mayor should have been calling on the UFT to come to the negotiating table. In all honesty, it never should have come to this.”

The City Council speaker, Gifford Miller, has said he thinks the current mayor has made a mistake not to negotiate a contract with the teachers.

“He thinks the mayor ought to be negotiating right now, but there’s one mayor at a time and he’s not going to negotiate the specifics of a contract through the press right now,” a Miller spokesman, Steven Sigmund, said.

Asked whether the Upper East Side Democrat would attend tomorrow’s rally because of politics or because of his support for teachers, Mr. Sigmund said: “For him, it’s always been about supporting teachers. If people want to refer to that as a political statement, they can. What’s important to the speaker is that we have the best and most qualified teachers in New York City classrooms for the city’s kids.”

The campaign office of the other Democratic candidate, Fernando Ferrer, did not return a call requesting comment.

The mayor and the schools chancellor, Joel Klein, both were invited to the rally, but their spokesmen said they probably would not attend.