Austin’s plastic bag ban is illegal according to Texas Attorney General Ken Paxton, who asked the Texas Supreme Court on Thursday to affirm an appeals court ruling that such bans are unlawful.

According to a press release from Paxton’s office, the attorney general filed an amicus brief that asked the state’s highest court to affirm an August 2016 decision by the San Antonio Court of Appeals that ruled a similar bag ban in Laredo was illegal.

Paxton’s argument cites the Texas Health and Safety Code, which forbids municipalities from creating rules that “prohibit or restrict, for solid waste management purposes, the sale or use of a container or package in a manner not authorized by state law.”

“Cities across Texas are failing to respect the rule of law and unlawfully passing the burden of municipal solid waste management to residents and retailers through bag bans,” Paxton said. “Municipalities do not get to violate Texas law merely because they don’t like it. We’re asking the Texas Supreme Court to uphold the law so that the ruling can be used to invalidate similar ordinances across Texas.”

Austin City Council unanimously approved the Single-Use Carryout Bag Ordinance in 2011, which went into effect in 2013. It was meant to encourage a shift to reusable bags through regulation.

City of Austin spokesperson Bryce Bencivengo said the San Antonio court’s ruling can’t be directly applied to Austin’s bag ban.

“Our position has been clear throughout this appellate process, which does not directly impact the city of Austin’s ordinance,” Bencivengo said. “Austin’s single-use bag regulations have been around since 2013 and have served as a model for engaging stakeholders to develop effective environmental regulation.”

The ban was nearly bagged during the latest legislative session, but Senate Bill 103 failed to make it out of the Senate’s Business and Commerce committee.