A ban on the sale of new “convertible pistols” in Connecticut – set to take effect in two days – is in limbo.

On Tuesday, Glock asked a federal judge in Bridgeport to temporarily block the new law. A ruling is expected by Wednesday evening, just hours before the law begins.

Starting Thursday, Connecticut gun stores can no longer sell “convertible pistols,” which are handguns that easily convert into an automatic weapon using a small part known as a “Glock switch.”

Pistols outfitted with the device can fire up to 1,000 rounds per minute.

“For years it has been this open secret that gun manufacturers have knowingly sold semi-automatic pistols designed to be easily converted into fully-automatic machine guns using a cheap, $25 piece of plastic,” said Jose Davila, with Everytown for Gun Safety, at a bill signing ceremony in June.

Glock is not specifically named in the law, but critics say its handguns suppress a mechanism that prevents them from firing multiple rounds at once.

“It’s any pistol manufacturer that creates a gun that can be easily converted into a machine gun,” Gov. Ned Lamont told reporters on April 22. “If there’s one manufacturer in particular that’s much more at risk there, clean up your act.”

On Tuesday, attorneys for Glock and a Wallingford firearms retailer asked Judge Kari Dooley to temporarily block the “confusing” ban.

Glock argued it that its new “triple block” design cannot be converted to an automatic weapon and said it’s unclear whether the ban applies to them.

That confusion means gun stores are afraid to order new Glocks, attorneys argued.

“Glock, Inc. requested the State’s position regarding whether the Slimline, V Series, and Gen6 GLOCK pistols are considered to be ‘convertible pistols,’” according to a court filing from the gun manufacturer. “The Connecticut Office of the Attorney General refused to respond.”

State leaders pushed back.

“Rather than provide a sample to the state for testing, Plaintiff ‘explained why’ its models ‘do not fall within the definition of a ‘convertible pistol,’” according to a response from the state attorney general.

Dooley raised concerns of her own. During oral arguments, she called the ban “messy” and suggested that “aspects of this law are virtually impossible to enforce, at least fairly.”

Dooley said she will issue a ruling by the “end of business” on Wednesday.

Dooley can do nothing and let this law take effect on Thursday, issue a temporary restraining order good for two weeks or issue a preliminary injunction, which lasts longer.

Last week, a federal judge upheld a similar law in Maryland. Glock is also challenging another ban in California.