Casting herself as a tenant rights advocate at the risk of alienating political kingmakers in the real estate community is a delicate balancing act for the speaker of the City Council, Christine Quinn.

Ms. Quinn, who is expected to run for mayor in 2009, introduced a bill yesterday that would allow tenants to take their landlords to Housing Court for harassment, opening the floodgates to a wave of new lawsuits. Cheering tenants crowded the steps of City Hall for the announcement, which was quickly denounced by real estate industry leaders.

But in a sign that Ms. Quinn may be able to appease both sides, those who said they oppose the tenant bill indicated that they would not punish the speaker over a single issue.

"Obviously, people will look at this who own rental apartment buildings, and they won’t be happy," the president of the Real Estate Board of New York, Steven Spinola, said. "But on a lot of other issues, she’s been terrific and very strong."

Mr. Spinola said he planned to talk to Ms. Quinn about making changes to the bill but wouldn’t say what he would propose amending. He predicated that the bill would clog up the courts and create nuisance lawsuits.

"This is going in the opposite direction of tort reform," he said.

Currently, tenants are allowed to take their landlord to Housing Court only when they are not receiving essential services, such as heat or hot water. Under the new bill, a tenant whose water is turned off and on repeatedly or whose locks are changed without being given a new key, for example, could claim harassment.

Landlords found to have harassed a tenant would face civil penalties ranging from $1,000 to $5,000 and a court order to stop the harassment, if the bill is approved.

"Development and growth in our city is a great thing, and it can do a lot to help neighborhoods move forward and expand, but we need to recognize that with development often comes gentrification pressures," Ms. Quinn said. "There are bad apples out there who are responding to that gentrification by deliberately and willingly engaging in campaigns of tenant harassment to get tenants out of their homes so they can rent them for much, much higher rents."

The director of government affairs for the Rent Stabilization Association, which represents building owners, Frank Ricci, said government agencies should be screening tenant claims before they go to court to ensure they have merit. He said tenants already have the option to direct their landlord harassment complaints to a government agency, which can take the landlord to court on their behalf.

When asked how the legislation would affect Ms. Quinn’s mayoral aspirations, Mr. Ricci said it would depend on what the final version of the bill says.

"In my personal opinion," he said, "she’s been very fair in a lot of these issues."