WASHINGTON — Cities, counties, public schools and community colleges around the country have limited or reduced the work hours of part-time employees to avoid having to provide them with health insurance under the Affordable Care Act, state and local officials say.

The cuts to public sector employment, which has failed to rebound since the recession, could serve as a powerful political weapon for Republican critics of the health care law, who claim that it is creating a drain on the economy.

President Obama has twice delayed enforcement of the health care law’s employer mandate, which would subject larger employers to tax penalties if they do not offer insurance coverage to employees who work at least 30 hours a week, on average. But many public employers have already adopted policies, laws or regulations to make sure workers stay under that threshold.

Even after the administration said this month that it would ease coverage requirements for larger employers, public employers generally said they were keeping the restrictions on work hours because their obligation to provide health insurance, starting in 2015, would be based on hours worked by employees this year. Among those whose hours have been restricted in recent months are police dispatchers, prison guards, substitute teachers, bus drivers, athletic coaches, school custodians, cafeteria workers and part-time professors.