A federal judge on Saturday temporarily blocked portions of an Arkansas law that would have made it a crime for librarians and bookstores to provide minors with materials deemed "harmful" to them.

The law, signed by Republican Gov. Sarah Huckabee Sanders in March, would have held librarians and book vendors criminally liable for knowingly making available to minors material that would appeal "to a prurient interest in sex." Under the law, the material would also have to lack "serious literary, scientific, medical, artistic, or political value" and be "patently offensive" under community standards.

The law, known as Act 372, would have taken effect Tuesday but will now remain blocked while the case plays out.

A group of libraries, librarians, several bookstores and publishing groups -- including the Arkansas Library Association and the Central Arkansas Library System -- filed a lawsuit last month arguing that a section of the law violated the First Amendment. The plaintiffs also challenged another section of the law that would have allowed individuals to challenge libraries over a material's "appropriateness."

The plaintiffs argued that the law could make way for the removal of libraries' "young-adult" and "general" collections with sexual content. They also said it could even lead to a ban of all persons under the age of 18 from entering public libraries and bookstores, due to "the risk of endless criminal prosecution."

Providing banned materials under the law to a minor would be a Class A misdemeanor and punishable by up to a year of jail or a $2,500 fine.

US District Judge Timothy L. Brooks of the Western District of Arkansas, an Obama appointee, ultimately agreed in his preliminary injunction, citing concerns about potential violations of the First and 14th amendments.

He described the law's definition of "appropriateness" as "fatally vague," arguing that it would be too challenging to enforce the law without infringing on constitutionally protected speech. Material deemed "harmful" for the youngest minors may be appropriate for the oldest minors or adults, Brooks said.

A spokeswoman for Sanders said the governor continues to support the law despite the ruling.

"The governor supports laws that protects kids from having access to obscene content and the idea that Democrats want kids to receive material that is literally censored in Congressional testimony is absurd and only appropriate in the radical left's liberal utopia," Sanders communications director Alexa Henning said in a statement to CNN.

The ruling is subject to appeal. CNN has reached out to Arkansas Attorney General Tim Griffin, a Republican, regarding potential next steps.

The American Civil Liberties Union of Arkansas, which represented some of the plaintiffs, welcomed the judge's injunction.

"It's regrettable that we even have to question whether our constitutional rights are still respected today. The question we had to ask was -- do Arkansans still legally have access to reading materials?" Holly Dickson, the executive director of ACLU Arkansas, said in a statement. "Luckily, the judicial system has once again defended our highly valued liberties. We are committed to maintaining the fight to safeguard everyone's right to access information and ideas."

Dickson previously called Act 372 "an Arctic breeze on librarians across Arkansas."

The plaintiffs included 17-year-old Hayden Kirby, who said in a statement that the law would limit her ability to "explore diverse perspectives." Kirby said she spent time in the library every day throughout middle school.

"To restrict the spaces I've accessed freely throughout my life is outrageous to me," she previously said in a statement. "I want to fight for our rights to intellectual freedom and ensure that libraries remain spaces where young Arkansans can explore diverse perspectives."

The American Library Association said in a report earlier this year that there were 1,269 demands to censor library books and resources across the country in 2022, marking the highest number of attempted book bans since the association began compiling the data more than 20 years ago.

Free speech organization PEN America found book bans rose during the first half of the 2022-2023 school year, in large part due to state laws in Texas, Florida, Missouri, Utah and South Carolina -- which accounted for almost a third of the bans, according to the report from April.

A new law signed in Texas last month banning books containing sexual content that is "patently offensive" was decried by opponents as potentially harmful to childrens' education.

Last month, President Joe Biden announced he plans to appoint a new federal coordinator to address the increase in book bans enacted across different states.