Lawmakers failed to override Gov. Chris Christie's veto of a bill requiring law enforcement agencies be notified when a prospective gun-buyer applies to expunge mental health records.
If lawmakers had succeeded, it would have been the first time they voted to override a Christie veto out of 52 attempts since he took office in 2010.
The Democrat-controlled chamber came within two votes of the necessary two-thirds majority to overrule the governor.
The legislation passed unanimously in June.
The bill would provide judges with the latest information on an applicant, including pending charges.
Before the vote, supporters of gun reform were hopeful for the override and encouraged lawmakers on both sides to keep this from becoming political.
"We believe this legislation can save lives and we stand not in name of politics, but in name of traditions, communities and peace," said the Rev. Lukata Mjumbe, of the United Mercer Interfaith Organization.
Senate President Steve Sweeney on Thursday postponed a final vote on the override vowing to revisit the measure later. Sweeney said that he will bring back the override vote as many times as it takes to pass it.
Christie conditionally vetoed the measure in August, saying it could confuse a cumbersome area of law.
The Associated Press wire services contributed to this report.