ALBANY—The State Senate can now post a simple sign on its door: “Closed.”

An attempt Thursday by a new Republican-led team of senators to start passing bills ground to a halt after one of two Democratic rebels balked and walked out of the chamber — leaving the razor-thin majority one vote short of a quorum.

Unless the situation changes when lawmakers return to the Capitol on Monday, it will be impossible for the Senate to pass any bills. That would be bad news for an array of interests, such as plans for new school construction in Buffalo and dozens of localities across the state that are awaiting legislative action on home rule requests.

Thursday, 30 Republicans and two Democrats made it to the Senate chamber for a session designed to show that Monday’s coup had succeeded. It was no easy feat for the delegation, which endured an attempt to block its members by protesters from two Democratic- leaning groups that were pushing, elbowing and shouting. One Rochester senator narrowly avoided being slammed to the floor.

But Sen. Hiram Monserrate, the Queens Democrat and one of the two rebels in the coup, said he would not cooperate with the coup unless more of his fellow Democrats came onboard.

“You can’t have coalition government with two Democrats and 30 Republicans. It’s just not reality,” he said, leaving surprised — and, in some cases, seething — lawmakers behind.

However, the coup backers maintained happy faces.

“My engines will never be on reverse here,” said Sen. Pedro Espada, the Bronx Democrat and new Senate leader. As he has since Monday, he predicted that more Democrats would join the coup.

In other developments, Espada alleged criminal harassment by unnamed people he said have been intimidating family members and health care clinics he founded. He also said that his Bronx house was burglarized Monday night — just hours after he led the coup — and that various files in his home office were stolen.

Espada and his Republican allies cheered when a state judge would not sign an order sought by Democrats to block the session. By afternoon, a Democratic appellate judge reversed the decision.

But the sides could not agree on what it meant. Democrats said it blocks Espada from serving as Senate president, thereby stopping further sessions. But Republicans insisted that it meant only that Espada could not serve as acting governor if Gov. David A. Paterson traveled outside the state.

Today, a state judge in Albany will consider the merits of the case.

Members of the GOP-led group said they wanted to begin passing bills Thursday but could not because the three-dozen bill jackets were locked in a desk by Democrats.

But Democrats said the bills under lock and key were not those that Republicans wanted to pass. They said the GOP concocted the story to avoid the embarrassment of Monserrate’s carrying through with his threat to vote “no” on any bill— including even his own measure, S. B. 4071, requiring the “sanitization of every used mattress or bedding material transported, stored or sold in the state.”

Espada said he had talked on the telephone with Paterson and that the governor backed him — and no longer Democratic Sen. Malcolm A. Smith — as the Senate president.

However, a Paterson spokesman denied that this was the case. “He does not recognize Sen. Espada as the Senate president,” Peter Kauffmann said.

The Capitol, meanwhile, is on life support.

The Assembly was in session this week passing bills, but those not yet approved by the Senate are on hold. In addition, negotiations have halted an array of matters, including how to slow property tax increases, the future of a major economic-development program and a bill to legalize gay marriage.

Come Monday, if nothing changes, Republicans will have 31 senators willing to act, one shy of votes needed to pass a bill.

Espada and his GOP allies hope to lure some Democrats to the floor by calling up bills they want passed.

Espada said he will put the gay marriage bill to a vote, something Smith said would happen only if it was certain to pass. So some Democrats will have to make a choice: stick with the boycott or come to vote on a bill they want enacted.

"We all want the Senate Democrats to come in and participate, and as I get the same-sex marriage bill on the floor, they'll take their seats," Espada predicted.

A week of anger and confusion boiled over outside the chamber. Two groups — Acorn and Citizens Action, which have alliances with Democrats — had protesters screaming and bumping into the senators.

Afterward, Sen. Dale Volker, R-Depew, said Democrats broke the chamber's rules by allowing the protesters to congregate in the lobby. Official Senate staff who help run the sessions were "intimidated'' by Democrats to not show up Thursday. Volker said Republicans are considering a lawsuit to get Democrats to "cease and desist hindering the Legislature."

The possibilities for how the legislative crisis ends are limited only by the imagination. More Democrats could flip to join the coup. Legal action could shape a course. A new Democratic leader could emerge with a new way to restore party peace. A true coalition — some sort of power sharing deal — is also possible, though remote.

Then there is the nuclear option: impasse. Suppose neither side blinks and there are not enough senators for a quorum to hold session. Democrats say it could force the house into adjournment, from which it could not emerge until January 2010. The only exception is if Paterson called a special session, during which only issues the governor chooses can be considered.

Austin Shafran, a spokesman for Smith, the deposed majority leader, said Republicans conducted "a sham of a session that was a tremendous sign of disrespect to the people of New York who voted for a Democratic majority.'' He said Republicans were "bought and paid for'' by B. Thomas Golisano, the Florida billionaire and owner of the Buffalo Sabres who supported the coup.

But Sen. George Maziarz, R-Newfane, said he is hoping Democrats oust Smith as their leader. "Then maybe cooler heads will prevail around here by Monday," he said.