It's been a rough three months for New York mayoral hopeful Christine Quinn, who has been pounded by a $1.5 million blitz of television ads, robocalls and mailings skewering her.

And it's not over yet.

Quinn, the City Council speaker, has lost a third of her support in the polls since the "New York City is Not for Sale" political action committee began its single-minded — and largely unanswered — spending spree to bring her down.

The PAC now says it plans to spend at another $1 million on attack ads through the Sept. 10 Democratic primary.

And while former congressman Anthony Weiner's entry into the race also has siphoned support from Quinn, the attack ads clearly have taken a toll.

"There is a direct correlation between the launch of our campaign and her numbers going down," crowed Scott Levenson, a spokesman for the PAC, which is financed by a coalition of Quinn opponents, including advocates who call horse-drawn carriages a form of animal abuse.

"You can argue about what percentage we contributed to [Quinn’s fall], but you cannot deny that we were one of, if not the major contributing factors."

In February, Quinn hit 37% support in a Quinnipiac University poll.

On April 10, two days after the ads began running, Quinn was at 32%. Nine days later, she was at 28%. By May 22, just before Weiner jumped into the race, Quinn's backing had dropped to 25%. And as of Thursday she was down to 19% — locked in a statistical tie with Weiner and former Controller Bill Thompson.

Because she is participating in the city's system of public campaign financing, Team Quinn is limited in how much it can spend. So it has chosen not to respond to the ads in order to save money for the furious final weeks of the primary.

Quinn spokesman Mike Morey concedes "weeks of attacks and millions of dollars on television ads certainly have an effect on polling," but says when the primary comes, voters will know Quinn's "record of delivering real results for middle class New Yorkers."

While polls fluctuate, "we are quite confident that we have an unrivaled campaign infrastructure, significant financial resources, and a robust turnout operation."

Still, these are anxious days for some Quinn supporters.

Hector Figueroa, president of local 32-BJ of the Service Employees International Union, which just endorsed Quinn, said he viewed Weiner as her primary threat.

"We ... are incredibly worried, totally worried about Anthony Weiner ... People are giving [him] the benefit of the doubt. I believe he's just out there for himself. We need to stop Anthony, and I believe if progressive Democrats start to look at the race that way, they are going to come to the same conclusion."

Stuart Appelbaum, head of the Retail, Wholesale and Department Store Union, said he had "no buyer's remorse" after endorsing Quinn in January.

"She's divided between her duties as speaker and as a candidate. Now that the budget's done and she's going to have more time to campaign, I expect to see her numbers go up. I don't see anyone with a better path to victory."

Appelbaum called it "a real mark of confidence that two major unions endorsed her [last] week, even after the polls came out. If people were panicked, they wouldn't get on board the train."