A new federal law threatens to take nearly $10 million in federal funding away from the Virginia Railway Express commuter line, prompting local lawmakers to turn to the state's top officials for help.

VRE officials learned last month that they might not receive the roughly $9.6 million in federal funding that they have received in years past, thanks partly to a new law that would place the money into Virginia's general transportation fund. The federal dollars account for about 10 percent of the commuter rail's roughly $90 million budget.

Once the money goes into the general fund, local lawmakers fear it could be diverted to organizations other than VRE. Such a diversion could cause VRE officials to cut 12 trains, raise fares or even shut down service completely.

The potential loss of VRE trains, which altogether carried more than 4 million passengers last year, has left many local jurisdictions fearing the worst.

"The money involved in this is so large that Plan B, if we don't get this money, is the liquidation of the VRE," said Fairfax County Supervisor John Cook, R-Braddock. "This is not our typical budget cut."

In response, the Fairfax County Board of Supervisors joined the city of Manassas and Wally Covington, chairman of VRE's Operations Board, in writing Virginia Secretary of Transportation Sean Connaughton to request that the money continue to be devoted to VRE.

Fairfax's letter was just part of the county's "full-court press" to save VRE, said Supervisor Penny Gross, D-Mason.

Lawmakers hope to convince Connaughton, and ultimately the General Assembly, to reword state law to ensure VRE receives the money it needs to fully operate.

Founded in 1992, VRE operates 29 trains from 18 stations, taking Northern Virginia residents into downtown D.C. each weekday from as far south as Fredericksburg. The lines transport an estimated 16,000 passengers each day, according to VRE statistics.

"With the 2013 legislative session only two months away, it is now imperative that VRE receive assurances that our funding source that has been afforded to us since our inception continue," Covington wrote. "None of [the proposed alternatives and cuts] are viable."

The General Assembly will decide on the funding -- and its destination -- during the 2013 session, which begins in January.