Mayor Michael Bloomberg's plan to end his popular $400 property tax rebate hit a major roadblock on Monday, as City Council members said they're prepared to fight the mayor to keep the rebate alive.

The clash came at the first of ten budget hearings being held this month to deal with the city's financial crisis.

"Taking it away is the very antithesis of an economic stimulus package," Councilman Lewis Fidler said of the property tax rebate, which Bloomberg introduced in 2004. "It's an extraordinarily bad idea and I think we here in the council believe you don't have the legal authority to do it without coming here for our approval, and I doubt you would get it."

To underscore the point, Finance Chairman David Weprin produced an document from the city's budget office that states that rescinding the $400 property tax rebate requires legislative approval.

Bloomberg, who was in Washington on Monday, said the city's dark financial outlook doesn't change either way.

"If we don't do that, we are going to have to cut another quarter of a billion dollars out of our expenses," the mayor said.

To that end, councilmembers on Monday proposed a host of new money-generating plans to help the city weather the economic storm and close a projected $4 billion budget gap. The ideas include a reinstatement of the commuter tax, a hike in the hotel tax, charging a fee for residential parking permits, and a doubling of the fee the police department charges businesses for private security.

Bringing back the commuter tax is particularly appealing to Bloomberg Budget Director Mark Page.

"As New York City's budget director, I am always eager for money we don't have to pay for that we can spend," Page told the council. "And the commuter tax, if we could get it back, fits that."

The debate over the budget will carry on as the series of hearings continues throughout the week.