Topeka ? Some workers who are injured on the job would receive lower benefits under a bill legislators sent Wednesday to Gov. Kathleen Sebelius.

The measure is designed to prevent employers from paying workers’ compensation benefits for medical problems the employees had before being hired. The issue arises when an accident aggravates an existing condition such as a bad back or weak knee.

Sebelius has repeatedly criticized the bill as unnecessary and harmful to workers, and legislators in both parties expect the Democratic governor to veto it.

The House approved the measure Wednesday on a 67-56 vote. The Senate approved the same version last month, 28-12.

Led by the Kansas Chamber of Commerce, business groups backed the bill, describing it as vital to improving the state’s job-creation climate. Lew Ebert, the chamber’s president, said Kansas has ranked behind other states in economic growth over the past 25 years.

“We’re just trying to get back to a level playing field so employers can fairly compete and so we can put more Kansans to work,” Ebert said after Wednesday’s vote.

Critics called the measure “the disposable worker bill,” arguing it would permit employers to deny benefits to workers who deserve them.

Sebelius noted during a news conference Tuesday that Kansas’ maximum weekly benefit of $467 for injured workers is lower than those in all but six states. Also, she said businesses’ insurance rates are significantly lower overall than they were in 1993, when legislators overhauled workers’ compensation laws.

Supporters of the bill would need two-thirds majorities in both chambers to override a veto, or 27 of 40 votes in the Senate and 84 of 125 votes in the House. Backers fell 17 votes short of the mark in the House vote Wednesday, suggesting a Sebelius veto would be sustained.

For decades, the state has guaranteed that employers won’t face lawsuits for most on-the-job injuries. In exchange, employers must cover employees’ medical expenses and provide additional benefits to make up for employees’ lost wages, up to $467 a week.

In the early 1990s, businesses’ insurance premiums were skyrocketing, and they were complaining that claims from workers took too long to resolve through an administrative process often involving lawyers. In 1993, legislators enacted changes designed to lower premiums, get workers back on the job sooner and lessen the need for attorneys.

Supporters of this year’s bill argue that under the 1993 changes, employers were supposed to pay lower benefits to workers if they had a pre-existing medical condition aggravated by an on-the-job accident. Since then, they argued, administrative judges reviewing claims have eroded that principle.

“This brings it back to that original intent,” said Rep. Don Dahl, R-Hillsboro, the chairman of the House Business, Commerce and Labor Committee. “It has gotten a little bit out of kilter.”

But critics said the bill, by rewriting laws dealing with pre-existing conditions, would encourage employers to seek out hard-to-document evidence about a worker’s medical past.

For example, Rep. L. Candy Ruff, D-Leavenworth, said an employer could argue that a worker’s disability was related to a high school sports accident or military service rather than an accident on the job, even if the worker had not experienced past symptoms and previously hadn’t been diagnosed as having a problem.