The Senate agreed Monday evening to reauthorize a federal ban on the manufacturing of plastic guns that can't be detected by security-screening devices, putting the finishing touches on a measure that will be sent to President Obama for his signature.

The move makes extending the plastic-gun ban, first imposed in 1988, the only firearms issue approved by Congress in the 360 days since last December’s mass shooting at Sandy Hook Elementary School in Newtown, Conn.

Sen. Christopher Murphy (D-Conn.), a leading advocate of new, stricter gun laws, said “We should be embarrassed” that Congress has otherwise failed to stem the flow of assault weapons since the Sandy Hook shooting.

But the plastic-guns ban prompted rare agreement among Democrats and Republicans in part because the National Rifle Association, which mounted a strong campaign against a series of gun control proposals in the spring, remained silent on the issue of extending the ban on plastic guns.

Senate Democrats attempted to amend the ban by including a ban on new firearms manufactured with 3-D printers, which are of great concern because they can be used to make a gun that would be considered legal even if the only metal piece was detachable. But the attempts failed Monday evening before the Senate approved renewing the ban by unanimous consent.