RICHMOND – Virginia lawmakers on Wednesday voted to bar private insurance companies that participate in the state's health insurance exchange from providing coverage for abortions.

Gov. Bob McDonnell proposed the restriction and sent it to the General Assembly as an amendment to another bill. The assembly, meeting Wednesday for a one-day, marathon veto session, approved the measure by narrow margins in both the House and Senate.

Under the new rules, a woman in Virginia who buys health insurance from the federally operated exchange will have to pay for her abortion out of her own pocket. The exchange is scheduled to open in 2014.

Sen. John Watkins, R-Midlothian, sponsored the original bill, which was intended to help state insurance regulators comply with the new federal exchange. Watkins said he was “disturbed” by the governor’s changes and unsuccessfully pleaded for his colleagues to reject them.

“The last thing we need is more bureaucrats telling patients what they can do and what they can’t do,” he said.

But supporters of the measure, largely Republicans, said the bill ensures taxpayer dollars won’t support abortions.

“All that the governor is doing is saying within Virginia we’re going to do what 19 other states have done and block taxpayer funding of abortions,” said Sen. Dick Black, R-Leesburg.

The final vote in the Senate was 20-19. Sen. Harry Blevins, a Republican who has long been considered the swing vote on social issues in the evenly divided chamber, initially said he would against the amendment, but then the retiring lawmaker reversed course and backed it.

Sen. Frank Wagner, R-Virginia Beach, did not vote on final passage.