AUSTIN, Texas — Texas’ highest civil court is discussing a border city’s ban on plastic bags and could ultimately decide to end such prohibitions statewide.

The Laredo Merchants Association is challenging its city’s ban on distributing single-use plastic bags at grocery stores and other shops.

The association argued before the Texas Supreme Court on Thursday that existing state law on solid waste disposal supersedes the local ordinance designed to prevent litter. Many Texas cities have plastic bag bans, including Austin.

A lower court sided with Laredo, but that was reversed on appeal, prompting state Supreme Court arguments.

Conservatives in the state Legislature have for years tried unsuccessfully to ban all local plastic bag bans.

A Supreme Court decision could undermine all such ordinances, though its nine Republicans justices likely won’t rule for months.