Governor Spitzer, in an interview with The New York Sun, rejected as pointless demands by Senate Republicans that he appoint a fellow Democrat, Attorney General Cuomo, as a special prosecutor to investigate the administration’s use of the state police against the Senate majority leader, Joseph Bruno.

Mr. Spitzer said he saw no need for Mr. Cuomo to conduct a special investigation into the scandal because the attorney general’s office has already cleared his administration of any criminal wrongdoing and because the New York State Ethics Commission is in the process of determining whether any further inquiry is warranted.

“It seems to me that the attorney general already issued a report that he called complete, and Joe Bruno already called it a complete report. We have the Ethics Commission doing its thing,” Mr. Spitzer said.

By opposing the appointment of a special prosecutor, Mr. Spitzer is essentially challenging the Senate Republican majority to carry out its threat to conduct its own investigation through Senate hearings with subpoena power. The governor has said his office would not cooperate with such an investigation.

Senate Republicans had preferred that Mr. Cuomo reopen the inquiry rather than taking charge themselves out of concern that Republican-led legislative hearings would be perceived as a partisan attack on the governor. If appointed special prosecutor, Mr. Cuomo would have subpoena power, an investigative tool he lacked during his office’s initial inquiry.

Republicans signaled yesterday that they would proceed with hearings anyway.

“The governor has invited the Senate to move forward to a full-blown investigation,” the chairman of the Senate committee on investigations and government operations, George Winner, said in an interview. “I think we’re headed in that direction as a result of the governor’s rejection of a special prosecutor.”

Mr. Winner said the attorney general’s office indicated to him in conversations that Mr. Cuomo would accept the assignment. A spokesman for Mr. Cuomo’s office, however, suggested that Mr. Cuomo was not interested in reopening the case. “The findings of our report speak for themselves,” the spokesman, Jeffrey Lerner, said in a statement.

Speaking to the Sun, Mr. Spitzer vowed that the facts in the case would be “clarified” despite growing public skepticism about his claim that he and his chief of staff, Richard Baum, were unaware of the plot to discredit Mr. Bruno by planting with the press state police records detailing his use of a state-owned helicopter on trips that combined political activities with public business. A Siena New York poll found that 51% of registered voters believe that the governor knew about the actions of aides against Mr. Bruno.

While speculation has grown in Albany that Mr. Spitzer will replace Mr. Baum as his most senior adviser as part of an overhaul of his inner circle staff, Mr. Spitzer said he was “absolutely” confident in Mr. Baum and that he “looked forward to working with him.” He said the staff changes under consideration are “a natural evolution that goes on within any office.”

Amid the growing turmoil, Mr. Spitzer said he was concentrating on his “day job,” while immersing himself in dozens of daily briefing memos, newspaper reports, and magazines. He said he’s been so consumed with work that he’s been deprived of the simple pleasures of life. The Princeton and Harvard Law School graduate said sheepishly that he hasn’t opened a book in months.

Two weeks ago, Mr. Spitzer appeared to be on steady footing. After months of negotiations, he finally clinched a deal with lawmakers that seemed to clear the way for new restrictions on campaign contributions, achieving one of the governor’s top priorities.

Last week, Mr. Cuomo knocked the administration on its heels, releasing a report that faulted the administration for plotting a campaign to discredit Mr. Bruno by authorizing the state police to dig up information about Mr. Bruno’s use of air and ground security escorts on days he attended fund-raisers. Administration officials hoped to find evidence that the Senate leader was using state resources for political purposes and leak it to the press, the report said. The report, however, found no evidence of criminal wrongdoing.

Since then, Mr. Spitzer has suspended his communications director, Darren Dopp, and demoted his liaison to the state police, both of whom the Cuomo report described as playing large roles in the plot against Mr. Bruno. At press conferences, Mr. Spitzer now faces nothing but questions about the scandal. His top aide, Richard Baum, has faced increasing scrutiny from Republicans who say that he is covering up his knowledge of the plot. Two other top administration officials, Sean Patrick Maloney and Peter Pope, have been taken away from their normal work to counsel the governor on how to respond to the allegations.

Mr. Spitzer said he would stick with his governing agenda. He said he was confident that lawmakers would pass several items of legislation that they informally agreed upon earlier in the month, while disputing Republican claims about the details of the agreement.

Republicans said Mr. Spitzer had signed off on a capital spending bill that would grant the Senate conference $300 million in discretionary economic development funds. Mr. Spitzer said the amount was a “ballpark figure.” Republicans also said they would withdraw their support for a proposal to tighten campaign finance laws if Mr. Spitzer did not approve a $200 million property tax rebate package for senior citizens.

Mr. Spitzer told the Sun that “no number was discussed” but said the deal with lawmakers would hold because “Senate Republicans…are individuals of good faith.”

The governor said that two private developers’ plans to move Madison Square Garden and renovate and expand Pennsylvania Station are “moving ahead at a record clip” but said he “couldn’t come close to giving you a date or a timeframe” for when the deal would be completed.

Senate Republicans, who say they suspect that knowledge about the plot against Mr. Bruno went much deeper than Mr. Spitzer says it did, said they had no plans to pass the legislation but were focused on getting to the bottom of the trooper controversy. They say normal state business cannot proceed until Mr. Spitzer and his aides answer questions they say have been unanswered by Mr. Cuomo’s investigation and by an inquiry led by the state inspector general, who was appointed by Mr. Spitzer.

They also say they are troubled by the fact that two top aides to the governor, Messrs. Dopp and Baum, refused to be interviewed by attorney general investigators and that the inspector general, Kristine Hamann, failed to issue any subpoenas, interview any senior administration officials, or issue a report.

Republicans have questioned the neutrality of the state Ethics Commission, which is led by a Spitzer appointee, John Feerick, the former dean of Fordham Law School.

The Spitzer administration has turned over to the ethics commission the same records that were used in the attorney general inquiry. The commission has yet to decide whether to launch a full investigation.

“By appointing a special prosecutor, the Governor could have moved to put this whole matter behind him. He could have assured the public that there is nothing to hide,” Mr. Bruno said in a statement. “He could have appointed an independently elected individual who could help satisfy the public’s right to know the truth. He could have restored confidence in him and his office so that we could return to other pressing issues before us.”

He continued: “However, it now appears that the Governor has rejected the call for a special prosecutor. This is the wrong decision because the public demands answers to many questions that still remain.”

Senate Democrats and Assembly Democrats have said they would be opposed to Republican-led investigative hearings.