WASHINGTON — The Supreme Court on Thursday declined to block a new Mississippi law that imposes age verification and parental consent restrictions on social media platforms.

In a brief order with no dissents, the court rejected an emergency request filed by industry group NetChoice on behalf of nine of its members, including Facebook, X and YouTube.

In a separate concurring opinion, Justice Brett Kavanaugh wrote that NetChoice had, in his view, “demonstrated that it is likely to succeed on the merits” when the case reaches a final conclusion but had not shown the need to block the law at an early stage of the litigation.

The law, enacted last year, requires all users under 18 to verify their age and for minors to obtain parental consent to access social media sites. It is aimed at addressing growing concerns about the negative impact of social media on young people.

NetChoice argued in court papers that the restrictions violate free speech protections under the Constitution’s First Amendment. The group represented six additional platforms in the case: Dreamwidth, Instagram, Nextdoor, Pinterest, Reddit and Snapchat.

Other states, including California, Georgia and Florida, have passed similar laws in recent years and were also challenged, but the Supreme Court has not yet weighed in. On a related issue, the court in June upheld a Texas law seeking to restrict young people’s access to pornographic content online.

The Mississippi law also required social media companies to make “reasonable efforts” to ensure minors are not exposed to harmful content.

Companies could be hit with $10,000 penalties for violating the law.

NetChoice’s lawyers said in court papers that the provisions force companies to effectively censor speech because some users, whether because they are unwilling to verify their age or cannot get parental approval, will not be able to engage in otherwise protected speech.

Mississippi is seeking to “fundamentally alter how its citizens can access fully protected online speech,” the lawyers wrote.

Defending the measure, Mississippi Attorney General Lynn Fitch wrote in her own brief that it “imposes modest duties on interactive online platforms that are especially attractive to predators.”

A federal judge had twice ruled the law was likely unconstitutional, but the New Orleans-based 5th U.S. Circuit Court of Appeals on July 17 said in a brief order that it could go into effect in full.