Two major trade groups representing social media platforms Facebook, YouTube, and Twitter are suing the Attorney General of Texas over a new state law that supporters say would limit the "censorship" of conservative users.

HB20, which passed in Texas earlier this month, bans social-media companies with more than 50 million monthly active users from censoring people because of "the viewpoint of the user or another person," the law states. It also allows users "banned from social media for their political beliefs" to sue the platform that banned them.

Tech companies say the law "would unconstitutionally require platforms like YouTube and Facebook to disseminate, for example, pro-Nazi speech, terrorist propaganda, foreign government disinformation, and medical misinformation," according to the suit.

The plaintiffs cite multiple court decisions defending a private company's right to editorial discretion under the first amendment. This includes a Florida law similarly targeting social media companies that was blocked by a federal judge in June.

Texas GOP leaders initially raised Big Tech censorship concerns following the US capitol insurrection that killed five people and injured more than 100 officers.

In response, several major social-media networks banned former president Donald Trump from their platforms citing a violation of their terms and services, in addition to blocking accounts linked to election misinformation.

"I will defend the First Amendment and ensure that conservative voices have the right to be heard," Paxton said in a statement. "Big Tech does not have the authority to police the expressions of people whose political viewpoint they simply disagree with."