To the surprise of many, one the city's largest public employee unions joined with business groups in opposing the proposed half-percent sales tax increase being considered for the March ballot.

The Committee on Political Education for SEIU, Local 721, which represents about 10,000 city workers, voted late Thursday to oppose the measure, which will be given final consideration by the Los Angeles City Council on Tuesday.

"The proposed half-cent sales tax is a regressive tax that would hurt middle-class workers in Los Angeles," said Bob Schoonover, president of the local. "Our members decided they just couldn't support it.

"The City Council ignored other revenue raising measures and did so by relying on polls narrated by real estate lobbyists."

Schoonover complained the proposal, advanced by Council President Herb Wesson, failed to conduct any independent study nor was it discussed with city workers.

"We agree that the city needs to raise revenue, but we think there are better smarter alternatives," Schoonover said.

Wesson has warned that without the sales tax, up to 1,400 workers could be laid off next year, including 500 police officers.

In taking the action, the union joins with the Valley Industry and Commerce Association in opposing the sales tax ballot measure.

"The VICA board agreed that raising the sales tax was unwise during these economically tumultuous times," VICA President Stuart Waldman said. "There is no question that the city of Los Angeles' budget needs help, but imposing one of the highest sales tax rates in the county in a struggling economy is not the answer."

Mayor Antonio Villaraigosa also has expressed reservations about the measure, saying his support is contingent on a number of actions by the council, including assurances the money would be used first for public safety and other city reforms would be implemented.

Wesson wrote back to the mayor, agreeing to most of his conditions and saying he hoped the mayor would work to pass the sales tax measure - expected to generate more than $215 million a year, which would cover most of the shortfall next year.

"Very few responsible spending cuts remain on the table," Wesson wrote. "With your help and support, we will put the city back on track to a more sustainable and efficient government for all Angelenos."