Supreme Court Justice Anthony Kennedy has denied an emergency request by the National Rifle Association to block enforcement of a California city ordinance that bans gun magazines capable of holding more than 10 bullets.
A court spokesman says Kennedy denied the request without comment.
The ban in Sunnyvale went into effect last week after 66 percent of voters approved it in November.
The NRA challenged the law, but a federal judge ruled that it does not violate the Second Amendment right to own guns for self-defense.
The 9th U.S. Circuit Court of Appeals in San Francisco denied the NRA's request for an emergency order to stop the ban from taking effect while it considers the appeal.
Kennedy oversees emergency appeals from California and other Western states.