Attorneys general from four U.S. states have filed a lawsuit to stop the Obama administration from handing over control of the internet to an international governing body.

The White House had planned to officially hand the reins of the internet address system over to a group of international stakeholders on October 1, but the states’ fears the move could be unconstitutional threatens to block one of Obama’s top tech initiatives.

The attorneys general for Arizona, Oklahoma, Nevada and Texas all signed on to the lawsuit this week that argues the Obama plan to hand over control of the internet in an illegal transfer of U.S. government property, and any such giveaway would require congressional approval.

The Internet Corporation for Assigned Names and Numbers (ICANN) is a non-profit group that handles oversight of internet domain names. Since its creation in 1998, ICANN has been under the control of the U.S. Department of Commerce, but the Obama administration began plans in early 2014 to relinquish that control, with the process coming to completion Friday.

ICANN is the authority that controls domain names for websites and individual IP addresses for internet users. Opponents of the transfer fear that it will lead to censorship of the internet, should countries with poor free speech records like Russia or China somehow gain control.

“Trusting authoritarian regimes to ensure the continued freedom of the internet is lunacy,” Texas Attorney General Ken Paxton said in a statement. “The president does not have the authority to simply give away America’s pioneering role in ensuring that the internet remains a place where free expression can flourish.”

Supporters of the transfer say it is a bipartisan initiative that’s been in the works for years, and any last-minute attempts to block it would be seen by the international community as an act of bad faith.

Assistant Secretary of Commerce Larry Strickling said at a conference earlier this year the best way to preserve internet freedom is to relinquish control from the U.S. government to those stakeholders who use and operate the networks that comprise it.

“Free expression is protected by the open, decentralized nature of the internet, the neutral manner in which the technical aspects of the Internet are managed and the commitment of stakeholders to maintain openness,” said Strickling.

Texas Senator Ted Cruz began pushing back against the ICANN transfer months ago, but - despite receiving recent support from Republican presidential nominee Donald Trump - failed to muster much backing among his congressional colleagues.

Cruz tried to block the internet transfer with an attachment to a high-profile spending bill, but with another potential government shutdown looming, the Senate chose not to include Cruz’s plan in a budget deal approved Wednesday. Members in the House of Representative also chose to pass on Cruz’s plan.

In the lawsuit filed Wednesday, the attorneys general allege the Obama administration’s plans violate the U.S. Constitution’s Property Clause, which says that only Congress has the power to dispose of property belonging to the U.S. The plan also violates the free speech amendment by “chilling free speech," the suit says.

The states "will lose the predictability, certainty, and protections that currently flow from federal stewardship of the Internet and instead be subjected to ICANN's unchecked control," the lawsuit alleges.

The suit is asking for a court order to block the transfer, but no hearing date has yet been set.

So far, no federal judge has issued a ruling that would stop the plan from taking effect Friday.