Within hours of receiving Mayor Bloomberg’s $48 billion preliminary budget proposal for fiscal 2006, the five Democrats and two Republicans who want to replace him in November said the mayor had misplaced his spending priorities.

They labeled it an “election year” proposal that failed to address the city’s long-term structural budget problems and even added problems by including a $400 property tax rebate. None of them opposed returning money to taxpayers, but they said the 18.5% hike approved two years ago should have been lower to begin with.

The Democratic front-runner, Fernando Ferrer, said Mr. Bloomberg’s proposal of nearly 200 pages highlighted the administration’s “misplaced priorities.” The former borough president of the Bronx attacked the mayor for being more concerned about his development plan for Manhattan’s West Side and a new football stadium for the New York Jets, a project that would use $300 million of city money.

“At a time when our schools are overcrowded, child-care costs are soaring, and too many students go without after-school programs, Mayor Bloomberg has chosen to put the business interest of a New Jersey billionaire ahead of New York’s kids,” he said in an e-mailed statement, referring to Jets owner Robert Wood Johnson III. “The fact is that for just one-third of the money that Mayor Bloomberg wants to give the Jets’ owner, the city could open an after-school program in every middle school in the city.”

Mr. Bloomberg has said building a stadium – proponents prefer to call it the New York Sports & Convention Center – is important for spurring the local economy, which eventually will help solve the city’s structural budget problems.

The speaker of the City Council, Gifford Miller, the one challenger who will have a key role in shaping the fiscal 2006 budget, said the mayor’s cuts were not as “draconian” as they had been in each of the last three years. But Mr. Miller said Mr. Bloomberg’s decision to put off school construction until a court case against Albany on education funds is resolved is tantamount to a cut.

“The mayor says that there are no cuts to education in this budget,” he told reporters during a news conference in City Hall, saying that “removing $1.3 billion from the education capital fund” was indeed a cut.

“It is certainly going to feel like a cut to the kids that are going to be left in classrooms that are overcrowded,” Mr. Miller said.

Mr. Bloomberg has said school construction planning has such a long lag time that waiting for the resolution of the Campaign for Fiscal Equity case won’t affect construction in fiscal 2006.

Both Mr. Miller, who represents the Upper East Side, and a fellow Democratic candidate, Rep. Anthony Weiner, who represents a Brooklyn-Queens district, homed in on what has become a regular criticism of the mayor: that he does not publicly battle Governor Pataki for more state funds. The mayor’s response is that he believes a good working relationship with the governor will ultimately be more fruitful for the city.

“The mayor’s philosophy, that you get more with sugar than you get with vinegar, sooner or later has to show some results, and it clearly hasn’t,” Mr. Weiner told The New York Sun. He and Charles Barron, a Brooklyn council member who is also running for the Democratic nomination for mayor, said the proposal was purely political.

All of Mr. Bloomberg’s challengers said yesterday that the mayor’s budget was full of risks, from assuming that the state and federal government will fill gaps to expecting labor contracts not to cost the city any more in fiscal 2006.

“While the mayor says that he has reduced the $3 billion deficit to $1 billion, it is predicated on a lot of uncertainties, like the fire, police, and teachers’ union accepting the negotiated settlements,” another Democratic candidate, the borough president of Manhattan, C. Virginia Fields, said.

The two Republicans in the race had their own concerns about Mr. Bloomberg’s inability to slash spending. A former minority leader of the council, Thomas Ognibene, called the city’s work force “bloated” and said the city’s Medicaid spending was “the biggest culprit” in draining taxpayer money.

The other Republican looking to challenge Mr. Bloomberg in the primary, Steven Shaw, an investment banker, predicted that the mayor would eventually agree, through negotiations with the City Council, to spending more than he has proposed. That, Mr. Shaw said, is unacceptable.

The deputy director for budget studies at the Citizens Budget Commission, Elizabeth Lynam, called Mr. Bloomberg’s proposal “no pain, no gain.”

“He is sort of taking a break from dealing with city’s imbalance between revenue and spending,” she said. “Basically. whoever is in office next year is finally going to have to reconcile that spending and revenue are growing at different rates.”