Washington ? Deep spending cuts by state and local governments pose a growing threat to an economy that is already grappling with high unemployment, depressed home prices and the surging cost of oil.

Lawmakers at state capitols and city halls are slashing jobs and programs, arguing that some pain now is better than a lot more later. But the cuts are coming at a price — weaker growth at the national level.

The clearest sign to date was a report Friday on U.S. gross domestic product for the final three months of 2010. The government lowered its growth estimate, pointing to larger-than-expected cuts by state and local governments. The report suggested that worsening state budget problems could hold back the recovery by putting more people out of work and reducing consumer spending.

Across the country, governors and lawmakers are proposing broad cutbacks — lowering fees paid to nursing homes in Florida, reducing health insurance subsidies for lower-income Pennsylvanians, closing prisons in New York state and scaling back programs for elderly and disabled Californians.

“The massive financial problems at the state and local levels have and will continue to restrain growth,” said economist Joel Naroff of Naroff Economic Advisors.

State and local governments account for 91 percent of all government spending on primary education, according to the Brookings Institution. And they provide 71 percent of higher-education spending. States also account for more than 70 percent of spending on roads, bridges and other infrastructure.

But those same governments cut spending at a 2.4 percent rate at the end of last year. And economists predict they will slash their budgets by up to 2.5 percent this year — potentially the sharpest reduction since 1943. The deepest cuts are expected to occur in the first six months of this year.

The worst cuts so far — 3.8 percent — came in the January-to-March period of 2010. That was the sharpest quarterly drop since late 1983, when the U.S. economy was recovering from a severe recession. Most economists think the cutbacks this year will exert an even bigger economic drag than last year.

Newly elected Republican governors are leading the charge. They’re acting on campaign pledges to shrink government to meet budget gaps. They favor smaller governments with lower taxes and less regulation, which they say will boost private-sector growth and job creation.

Some Democrats — including Govs. Andrew Cuomo of New York and Jerry Brown of California — have followed suit. They’re pushing for cuts to social programs and concessions from unions.

No state has attracted more attention than Wisconsin. Pointing to the state’s projected $3.6 billion gap, Republican Gov. Scott Walker wants to strip state workers of collective bargaining rights. He also wants them to contribute more to their pensions and health insurance costs.

The budget fight has taken center stage in Congress. Democrats are bending to Republican demands for spending cuts to avoid a shutdown of the federal government next week.

The reduction in federal spending has a direct effect on states and municipalities. They depend on money from Washington to keep schools operating, put police officers on the street and subsidize public services like job training. The end of federal stimulus programs is also widening state deficits.

Many governors, including those in Florida, New York and Colorado, are pursuing tighter budgets. Proposals include laying off public workers and teachers, reducing spending for education and health care, and ending some social services.