A Government Accountability Office study quietly released Thursday has bolstered a Republican senator’s efforts to force Amtrak's rail service to accommodate gun toting riders or face shutdown, Raw Story has found.

The GAO ruled Thursday that an amendment inserted into a transportation funding bill by Republican Sen. Roger Wicker (R-MS) was permanent law, erasing doubts that Amtrak would have to comply. The mandate would force Amtrak to reverse a longstanding rule banning passengers from bringing guns onto trains instituted after 9/11.