— The Virginia General Assembly, reconvening Wednesday for a one-day session to consider legislation vetoed or amended by Gov. Robert F. McDonnell, gave its final approval to a landmark transportation-funding plan that the governor said would raise nearly $6 billion over five years.

The GOP-led House of Delegates and the evenly divided Senate backed several suggested changes from the governor, including a reduced fee on hybrid cars and technical changes intended to ensure that the bill’s provisions to raise additional taxes in Northern Virginia and Hampton Roads would pass constitutional muster.

But the bipartisan spirit that coalesced around the historic compromise on transportation soon evaporated as the legislature voted to adopt an amendment by McDonnell that would forbid insurers in federally managed exchanges under President Obama’s health-care plan from covering most abortions.

McDonnell (R) said the amendment — blocking coverage for abortion except in cases of rape, incest or a threat to the mother’s life — would conform with a law passed by the legislature in 2011. But Democrats said the measure would effectively block some women from access to abortion.

“It’s just a further attempt to expand the assault on women’s reproductive rights in the commonwealth,” said Sen. Ralph S. Northam (D-Norfolk).

But Republicans said the amendment was intended to ensure that public money is not used for abortions.

“This bill in no way, shape or form eliminates anyone’s ability to abort their child. It does address, however, how — rightfully — how taxpayer funds will be used,” said Sen. Thomas A. Garrett Jr. (R-Louisa).

He also rejected criticism from several Democrats that the amendment demeans women. “It’s hard for me to conceive of something more demeaning than new life tossed into a refuse can, a garbage can,” Garrett said.

Senate Democrats tried to derail the amendment procedurally, saying it was too far-reaching and thus not closely related to the original bill. Lt. Gov. Bill Bolling (R), who presides over the Senate, ruled that the governor’s amendment was germane.

Senate Minority Leader Richard L. Saslaw (D-Fairfax) appealed, thereby putting Bolling’s ruling to a vote of the entire chamber. But that vote also deadlocked, and the override failed. The governor’s anti-abortion amendment ultimately passed, 20 to 19.

The Family Foundation of Virginia, which opposes abortion, and the Virginia Catholic Conference applauded McDonnell’s amendment. But Planned Parenthood, which supports abortion rights, said the amendment would prohibit women from buying health insurance plans that include a “full range of reproductive health care.”

Wednesday’s meeting — devoted exclusively to bills vetoed by the governor following the legislature’s regular 46-day session or marked up with suggested changes — also reopened hotly contested debates over the proposed expansion of Medicaid under Obamacare. Lawmakers also dealt with dozens of bills passed during the annual session, including a two-year moratorium on the use of drones by law enforcement except in limited cases.

On transportation funding, the House voted 64 to 35 to approve the governor’s amendments, despite complaints from members of his own party that the bill was larded with taxes and could be unconstitutional.

“This is very much like Washington,” Del. Robert G. Marshall (R-Prince William) said in opposing the measure. “You have to pass the bill to find out what you’re doing and why you’re doing it.”

The transportation deal reached by lawmakers in the final days of that session was a drastically overhauled version of a plan McDonnell submitted at the beginning of the session. McDonnell’s amendments included reducing the $100 fee on alternative-fuel vehicles to $64, and dropping the vehicle titling tax from 4.3 percent to 4.15. He also suggested reducing the lodging tax from 3 percent to 2 percent to keep hotels in Northern Virginia competitive.

McDonnell also changed the legislative language concerning the regional taxation authorities after Attorney General Ken Cuccinelli II (R) advised they could be unconstitutional in their current form.

The compromise specifically includes the establishment of transportation funds for Hampton Roads and Northern Virginia.

Cuccinelli, who is running for governor this year, warned that, with few exceptions, the state constitution does not allow the General Assembly to impose special taxes on geographic areas.

The governor’s proposed amendments redefined the regional tax authorities in terms of population and traffic use, instead of geography. The changes call for population thresholds of 1.5 million residents, 15 million transit trips a year and 1.2 million registered vehicles before a new basis for tax can be established. Currently, only Northern Virginia and Hampton Roads meet those criteria.

Del. Ben L. Cline (R-Rockbridge) said Wednesday the bill could have unintended consequences, saying other localities could band together to meet the criteria and qualify for the regional tax funds.

The Senate and House also bade farewell to several members, including Del. Lacey E. Putney, who was the longest-serving member of the Virginia legislature. Putney, an independent from Bedford County who caucused with Republicans, was first elected in 1961.

“It’s not often that I’m speechless, but I hardly know what to say today,” Putney told his fellow delegates. “I feel like the mosquito at the nudist camp. There is so much territory to cover, you don’t know where to start.” Among the eight departing House members besides Putney were five Republicans and two Democrats, including Del. James M. Scott (D-Fairfax).

In the Senate, Harry B. Blevins (R-Chesapeake) surprised some colleagues by announcing that he, too, would retire. Blevins, 77, a retired high school principal, was often considered a swing vote on controversial measures.

At the governor’s request, the General Assembly also agreed to soften the blow of stricter new penalties for texting while driving.

The original measure would have imposed a $250 fine for a first offense and $500 for subsequent offenses. It also would have created a mandatory minimum fine of $500 on any driver convicted of reckless driving while texting. The governor recommended cutting those fines in half.

Lawmakers continued to work late Wednesday night and had yet to decide on proposed judges.