In a day of political theater for Mayor Michael Bloomberg and two of his would-be successors, Public Advocate Bill de Blasio accused the mayor of a bias against businesses outside Manhattan, Council Speaker Christine Quinn released a plan to cut fines for street vendors—and the mayor lambasted them both.

Public Advocate Bill de Blasio charged in a report released Thursday that Mayor Michael Bloomberg's administration dramatically increased the number of inspections and fines issued against New York City businesses during the economic downturn, "nickel-and-diming" small businesses in the boroughs outside Manhattan with a disproportionate burden of this "hidden" tax.

Between fiscal years 2010 and 2012, the city's Department of Consumer Affairs increased inspections by 66%, increased violations issued by 153%, and increased revenue from fines by 102%, according to Mr. de Blasio's report. During the same time period, the city's Department of Health and Mental Hygiene increased inspections by 55%, increased violations issued by 73% and increased fine revenue by 90%. The two agencies combined have increased annual fine revenue to $66 million in fiscal 2012, compared with $16 million in fiscal 2002.

The report, titled "Borough Bia$: How the Bloomberg Administration Drains Outer Borough Businesses," shows that businesses in the Bronx were inspected by Consumer Affairs 8% more frequently than the citywide average during the past decade. Businesses in Manhattan, for example, received 14% fewer inspections during that time period.

The report "shows a clear pattern of targeting the outer boroughs and going to them to take revenue out of small businesses that could not afford it," Mr. de Blasio said during a news conference outside City Hall. "The mayor has been balancing his budget on the backs of these businesses."

Coining a word, Mr. de Blasio called this type of discrimination "boroughism" defined as "clear bias according to borough."

Ms. Quinn's office sent out a press release about 30 minutes before Mr. de Blasio's press conference announcing the council will pass a package of legislation next week to reduce vending fines. The bills will cap maximum fines at $500 and will prohibit vending near hospital no-standing zones, taxi stands and within 20 feet of residential building exits.

Mr. de Blasio, a Democratic candidate for mayor who lives in Brooklyn, facetiously called the timing of Ms. Quinn's announcement a "stunning coincidence." Her office denied making the announcement in hopes of stealing Mr. de Blasio's thunder.

For his part, Mr. Bloomberg denounced Mr. de Blasio's report and promised to veto Ms. Quinn's proposal. The speaker is the frontrunner in the race for the Democratic mayoral primary and a close ally of Mr. Bloomberg.

Responding to Mr. de Blasio, the mayor said he isn't "going to sit here and answer every one of their campaign slogans."

"If you want to have people not do something society's thought they shouldn't do, you raise the fines, you don't reduce the fines," he said in response to the report. "Fines are very different than taxes. Fines are easy to avoid. You can't avoid taxes. Just don't do what we're trying to prevent you from doing, and you won't have the problem."

According to the mayor's office, during the past 10 years, businesses in the Bronx, Brooklyn, Queens and Staten Island have opened and created jobs at a faster rate than those in Manhattan.

Referring to the street vendor proposal, the mayor said, "I think reducing the fines is one of the stupider things I've ever heard."

Ms. Quinn defended the legislation, saying there will be escalating fines to deal with law breakers. "But the guy or gal who makes one honest mistake, let's not whack the heck out of them for no reason," she said.

Mr. de Blasio also lambasted Ms. Quinn for failing to combat what he called this pattern of inequity highlighted in his report.

"It is the responsibility of the City Council leadership to do something to stop it and it hasn't happened," Mr. de Blasio said. "It doesn't surprise me that Speaker Quinn did not put pressure on this mayor to change these policies."

Justin Goodman, a spokesman for Ms. Quinn, said the council in the fall 2009, under her leadership, created a penalty-relief initiative that saved businesses and individuals $36 million in fines and interest. The council was also involved in a program that reduced by more than two months the time it takes for new restaurants to get city permits and inspections.

"Her record on supporting small businesses in New York is second to none," Mr. Goodman said.

Mr. de Blasio suggested that the boroughs outside Manhattan are getting hit harder because many of these businesses are owned by immigrants and it might be easier for the city to collect fines from them.

Frank Garcia, chairman of the New York State Coalition of Hispanic Chambers of Commerce, attended Mr. de Blasio's news conference, and described the mayor and Ms. Quinn as "bullies" to small businesses.

"Hispanic businesses are going under. They cannot deal with this issue. I asked the mayor to stop," he said. "Now, we got proof and we are going to fight as much as we [have to] to make sure the mayor doesn't hurt our Hispanic and minority businesses no more."

Mr. de Blasio said he was forced to sue the Bloomberg administration to get the data, an allegation the mayor's office says is untrue. The city handed over the data when it was compiled, the mayor's office said.

—Laura Nahmias contributed to this article.

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