Mayor Bloomberg’s offer to use taxpayer dollars to pay for a criminal defense lawyer for the speaker of the City Council, Christine Quinn, and possibly for other council members, is a sharp departure from practice in Washington, where public officials who may have violated criminal statutes almost always pay for their own defense.

The federal government usually covers legal fees in civil or administrative cases, but rarely in criminal cases, a former federal prosecutor who has represented President Clinton, Senator McCain, and two former secretaries of defense, Robert Bennett, said.

“It would be more uncommon in criminal cases, and I can’t really think of one off the top of my head where an individual working for a public entity was able to go out and hire a lawyer and have the government pay for it,” he said.

When Mr. Bennett was told that the criminal defense lawyer hired to represent Ms. Quinn, Lee Richards III, is charging $600 an hour, he said he thought that the rate was “pretty unusual.”

“Normally when the government pays, there are rates that are significantly less than that,” he said. Governments often pay a discounted rate when hiring private lawyers.

Investigators have been examining a long-standing council practice of hiding money behind fictitious groups in the city’s budget to create a slush fund that the speaker could dip into during the year to reward favored council members or local organizations. Lawyers have said that intentionally putting false information into an official document, such as the city’s budget, violates New York State law and sometimes counts as a felony.

Mr. Bloomberg has defended the use of taxpayer dollars to pay for legal representation for council members and employees, saying that until there is evidence they have done something illegal, the city will provide them with counsel.

In addition to Mr. Richards, the council has hired the law firm Sullivan & Cromwell to represent the council and is in negotiations with a third law firm to represent council employees who have been asked to provide information to the U.S. attorney and Department of Investigation. The negotiations are ongoing, a spokeswoman for Ms. Quinn said yesterday.

The speaker has said she is not the target of an investigation by the U.S. attorney’s office and the Department of Investigation into the council’s finances and budget.

Council members, meanwhile, are awaiting a memo from Ms. Quinn’s aides explaining whether they can or need to hire a lawyer to represent them during the investigation.

Two council aides were indicted earlier this month on charges that they embezzled some $145,000 from a city-funded community organization, allegedly sending $31,000 to friends and relatives in Jamaica and giving $18,000 to a political club headed by Council Member Kendall Stewart of Brooklyn, who employed the aides on his staff.

Some of the money the city gave the group passed through two fictitious organizations in the city’s budget.

The chairman of the New York State Conservative Party, Michael Long, said he thinks it is “absolutely ludicrous” that taxpayers are footing a legal bill to protect council members “for actions they have brought on themselves.”

“We aren’t talking about a citizens group suing the City Council over a governmental issue. We are talking about lawyers being hired to protect the alleged possibility of wrongdoings and wrong activities by particular council members,” he said.

Mr. Long called the slush fund a tool “to buy off special interest groups for elections.” “And now we are going to have the taxpayers pay to protect the very members who have involved themselves in alleged misconduct,” he added.

With the exception at least one council member, Tony Avella, council members are defending the use of public funds to pay for the legal bills. Mr. Avella, who is running for mayor, has told The New York Sun that the city should not pay for lawyers to represent anyone who has done something illegal, and he said he did not know who was checking to make sure officials and employees represented by outside law firms had not broken the law.

A former state attorney general who represents parts of the Bronx on the council, Oliver Koppell, said he is growing frustrated with the idea that the hiring of lawyers with public funds is somehow wrong.

Mr. Koppell said his understanding is that the lawyers would represent people who are caught up in the investigation but have not been shown to have committed any wrongdoing.

“It’s perfectly appropriate,” he said.