Published: Jun 11, 2013 11:35 PM EDT

WASHINGTON (AP) - Ambitious legislation to stanch the growing number of sexual assaults in the armed forces by overhauling the military justice system faces an uncertain future due to vigorous objections from senior Defense Department leaders and key members of Congress who are concerned the proposed changes go too far.
    
The bill crafted by Sen. Kirsten Gillibrand, D-N.Y., cleared an important hurdle Tuesday when the Senate Armed Services personnel subcommittee that she chairs approved the measure. But the legislation must get through the full committee and its chairman, Sen. Carl Levin, D-Mich., has signaled his intent to offer an alternative that would mute the most aggressive reforms in Gillibrand's bill.
    
Gillibrand's legislation would remove commanders from the process of deciding whether serious crimes, including sexual misconduct cases, go to trial. That judgment would rest instead with seasoned trial lawyers who have prosecutorial experience and hold the rank of colonel or above. Her bill also would take away a commander's authority to convene a court-martial. That responsibility would be given to new and separate offices outside the victim's chain of command.
    
But Levin and other lawmakers, echoing fears voiced by the Joint Chiefs of Staff, believe that cutting commanders out of the legal process would undermine their ability to enforce good order and discipline within the ranks.
    
"Commanders ought to have and use the tools that are the most effective in terms of changing climate and affecting the behavior of people in their units, and that's to have available to them the power to send to a court-martial," Levin said Monday.