A bitter dispute in the Northern Virginia delegation erupted into public view today when three Fairfax County senators helped kill a health care bill to punish its chief sponsor, Arlington Del. Mary E. Marshall.

All three senators, who had voted for Marshall's bill Monday when the Senate approved it 20 to 19, voted no or abstained when the Senate reconsidered today and defeated the measure 22 to 15. The senators later acknowledged they had changed their positions to get back at Marshall for her efforts to gut Fairfax's top legislative priority, a highway bill that will be considered in committee Thursday.

She's carrying on a vendetta against Fairfax; she's been carrying it on for years, and everybody knows it," said Sen. Richard L. Saslaw (D-Fairfax), who sponsored the Fairfax bill. "If she still insists on rubbing our faces in it, well, fine, but she's not going to get off scot-free."

"I think they're idiots," responded Marshall, a Democrat who was first elected in 1965. "I don't play that kind of politics at all, ever. I think things should be considered on their merits."

Marshall's bill, which would have made it easier for home nursing services to get state licenses, was favored by senior citizens groups but opposed by nursing home operators, hospitals and insurers. Sen. Edward M. Holland (D-Arlington), who supported the bill, said it might not have passed even with Fairfax's help, but he criticized the delegation for holding a proconsumer bill hostage.

"This is, I suppose, Saslaw's version of hardball," Holland said. "To me, it's nothing but bush league to come down here and play games that result in the defeat of meritorious legislation . . . . I don't think I've been intimately involved in anything as brazen as this."

Saslaw has sponsored a bill for the Fairfax supervisors that would lift the $10 million annual limit on county spending on roads.

Fairfax could spend more of its own money, assuming what has been a state responsibility, but Marshall objects because the state will have to maintain roads the county builds.

Calling the measure "the great Fairfax treasury raid," Marshall proposed an amendment that would shift the cost of maintaining roads built or improved by the county from the state to the county. Saslaw said the amendment would ruin the bill, and he enlisted his Fairfax colleagues to help kill any measure Marshall sends to the Senate unless she backs down.

Sen. Clive L. DuVal 2d (D-Fairfax), who abstained today, joked that he "just didn't happen to be in my seat," but Sen. Joseph V. Gartlan Jr. (D-Fairfax) was more forthright.

"My vote had nothing to do with the merits," Gartlan acknowledged, adding that he had never participated in a similar situation in his 12 years in the Senate and wished this fight had been averted.

"I've been unhappy with this situation in terms of the effectiveness of the Northern Virginia delegation," Gartlan said. "I'm very concerned about the long-term impact of a situation like this. You live by the sword, you die by the sword."