by Kathleen Lucadamo

Mayor Bloomberg’s bare-bones budget for next year will slash the city work force by 23,000 and drastically increase its sales tax, officials revealed Thursday.

The plan hinges on the shaky prospect of help from the federal and state governments and from stubborn unions.

The mayor will introduce his executive budget today; it also calls for cuts in big-ticket construction projects and for city employees to cough up cash for health care, according to those briefed on the plan.

Homeowners will lose their $400 rebates – but won’t be hit with new property taxes, a proposal City Council members had vowed to block.

Although Bloomberg would not hike income taxes, he is pushing for a $900 million increase in the city’s sales tax, officials said. The proposal would raise the sales tax to 8.75% from 8.375%, officials said.

“It’s not a good-news budget,” said City Councilman David Weprin, who chairs the Finance Committee.

Bloomberg’s scaled-back plan plugs a $4billion deficit, but officials warned that the work force will shrink further if the state and feds don’t approve reforms to city pensions, employee health care contributions and Medicaid relief.

“In order to close this deficit without destroying the core services New Yorkers rely on, the mayor will need help from all of our partners, from the municipal unions to the leadership in both the state and nation’s capitol,” said Deputy Mayor Ed Skyler. “We all will have to do our part to get through these tough times,” he said.

Bloomberg proposes to reduce the city head count by approximately 23,000, a feat he plans to achieve through layoffs and attrition.

Among those on the chopping block will be roughly 15,000 teachers and other educators, a move United Federation of Teachers President Randi Weingarten warned “would be devastating” to schools.

The budget also includes another 3,000 job cuts that Bloomberg announced last year, including eliminating this month’s Police Academy class and firing 500 Housing Authority workers.

The Council has until July 1 to approve his fiscal blueprint, which is likely to change dramatically if Albany comes through with school funds or the economy takes another nosedive.

Gov. Paterson’s budget shaves $770 million from city schools.

The city staved off a deeper budget gap for next year because Bloomberg and the Council in November raised property taxes 7% and trimmed $1.5 billion from all agencies. Even with those measures, the deficit hovered at $1.3 billion and swelled in recent months because of dwindling tax revenue. Bloomberg’s doomsday budget comes as Controller William Thompson released a report Thursday that shows the city lost 65,000 jobs between October and December.

Thompson also found sales tax collections had dropped 5.1% in the last quarter of 2008, Manhattan office vacancies rose to 8% and the average market value of one-family homes in the city fell 6.8%.

The bleeding is not likely to stop.

The Independent Budget Office pegs the city budget hole over the next 2-1/2 years at $11.3 billion.