Five Amtrak unions were cleared by a federal judge Thursday to stage a one-day strike but it was not clear whether if any stoppage would take place.
U.S. District Judge James Robertson rejected a motion by Amtrak to block the walkout originally scheduled for Oct. 3, saying it would not violate labor law, Reuters reported.
A walkout would shut down Amtrak service for 65,000 daily passengers and disrupt heavily used commuter routes across the country.
The threatened strike was tied to union complaints that Congress was not adequately funding the money-losing railroad.
"While there is currently nothing preventing them from striking now we've asked the union to advise us when they intend to walk out," said Amtrak spokesperson Cliff Black.
According to a union official, no decision has been made on whether to set a new strike date.