The fate of legislation that would clear the way for a commuter rail system in central Florida remains in doubt.

Senate floor debate is set for Tuesday afternoon _ if the bill can clear two more committees before then.

The measure easily passed in the House on Monday but a few hours later barely won approval from the Senate Transportation Committee on a 5-4 vote.

Florida's two U.S. senators, meanwhile, have stepped up their efforts on behalf the bill.

They sent Gov. Charlie Crist and legislative leaders a letter again warning that Florida would lose any chance of getting $2.6 billion in federal stimulus dollars for a high-speed rail line between Orlando and Tampa without an Orlando area commuter system.