NEW YORK, NY July 03, 2009 —The Working Families Party says it'll endorse a candidate in the New York City mayor's race in the next week or so, and after a packed candidates forum in midtown last night, the party has a lot more to go on.

The three main candidates running for city hall each took their turns at the podium, including the incumbent. Mayor Bloomberg made his case for a greener City to the party, which describes itself as progressive and pro-labor.

BLOOMBERG: There are parts of our city where kids go to the hospital with four times the normal rate of asthma. it is a disgrace. One of the ways to stop that incidentally was congestion pricing.

REPORTER: The packed audience of more than 400 Working Families Party supporters applauded Bloomberg at several points, but he also got a smattering of boos and hisses when a questioner took the Mayor to task for using his fortune to fuel his record-breaking campaign spending.

Meanwhile, Queens Councilman Tony Avella is running a shoestring campaign for mayor, and last night, he cast himself as the incumbent's foil.

AVELLA: My race against Mike Bloomberg would get national attention because it is the average guy against the billionaire, the non-political person against the guy who has all the influence.

REPORTER: He also attacked the mayor's move to repeal term limits so he could run for a third term. And Avella said his own record of opposing developers makes him a good choice for New Yorkers who want change in city hall.

The other Democratic challenger - Comptroller Bill Thompson - focused on dollars and cents. He criticized the Bloomberg Administration's push for a half percent sales tax increase.

THOMPSON: It works against mid class and working new yorkers. it works against families in need, and it works against our small businesses across the city of new york.

REPORTER: It's unclear when and if the city's sales tax increase will take effect, because the gridlocked state senate has yet sign off on it.

In addition to an endorsement, the mayoral candidates are seeking the Working Families Party line on the ballot this fall. In the last mayoral contest, Mayor Bloomberg garnered enough support to deny the ballot line to former Bronx Borough President Fernando Ferrer, dealing a blow to his bid for City Hall.