WASHINGTON – The House of Representatives voted 248-179 Thursday to pass a bill that would rewrite the health care law to redefine a full-time job as 40 hours per week, reversing the 30-hours-per-week definition prescribed by the Affordable Care Act out of concern the current rules give employers an incentive to slash workers’ hours.

The bill would change the threshold for full-time work from 30 hours to 40 hours, which would exempt more businesses from the provisions of the Affordable Care Act’s employer mandate. That mandate requires that employers with 50 or more full-time workers provide health insurance or pay fines, but Congressional Republicans fear it gives companies an incentive to trim weekly hours to 29 or fewer to avoid penalties.

“Obamacare’s arbitrary 30-hour workweek puts 2.6 million Americans at risk of having their hours cut,” said Rep. Diane Black, R-Tenn.

The U.S. Chamber of Commerce strongly supports the legislation and sees it as a win-win. “By reverting back to the traditional definition, employees and employers would both be protected,” R. Bruce Josten, vice president of the Chamber of Commerce, said in a statement. The Chamber sees this vote as important enough that it may be included in its “How They Voted” scorecard ahead of the 2014 midterms.

Democratic lawmakers think this issue is overstated. “Businesses either operate with a substantially part-time work force, or they use mostly full-time workers,” House Minority Whip Steny Hoyer, D-Md., said in a statement. “Most employers do not fully retool their business practices and cut full-time employees down to 29 hours just to avoid the coverage requirement.”

Further, House Democrats point to a recent report from Congressional Budget Office and the Joint Committee on Taxation, which estimates that a change to the 40-hour work week would cause as many as 1 million Americans to lose access to employer-provided health coverage and almost 500,000 would become uninsured. The CBO estimates the bill could add $74 billion to the deficit over 10 years, and it is presented without an offset.

“This rather perverse bill raises the healthcare costs to everyone by reducing the number of insured,” said Rep. Jim McDermott, D-Wash. “The ACA is not going away, it is here to stay.”

To that end, the likelihood of the bill passing the Senate is slim, like the preceding 51 attempts to repeal the Affordable Care Act. Should it reach his desk, President Obama has pledged to veto the legislation.