The Supreme Court on Wednesday blocked broadcast of the first federal case to challenge the constitutionality of a gay marriage ban.

Chief U.S. District Judge Vaughn R. Walker is presiding over Perry v Schwarzenegger, now in its third day. At issue is the constitutionality of Proposition 8, the gay marriage ban approved by voters in 2008.

Walker green lit a plan to broadcast the trial in other federal courthouses in California, New York, Oregon and Washington. He was also considering posting footage of the trial on YouTube, the video-sharing website owned by Google.

Supporters of Proposition 8 submitted their last-minute appeal to the Supreme Court on Saturday.

In a 5 to 4 decision, the Supreme Court chastised the trial court for attempting “to change its rules at the eleventh hour.”

“The broadcast in this case should be stayed because it appears the courts below did not follow the appropriate procedures set forth in federal law before changing their rules to allow such broadcasting,” the court said in an unsigned 27 page ruling.

Walker was acting after a pilot program that would for the first time allow cameras in civil trials was approved by the governing body for federal courts in Western states. But justices disagreed. Calling the trial “divisive,” they said it was “not a good one for a pilot program.”

Challengers to Proposition 8 had welcomed the broadcast. A coalition of media organizations, including network broadcasters, CNN and Court TV, had also argued in favor of allowing cameras in the courtroom.

“If there is a public benefit to public trials – and there is – then there is also a public benefit to complete access to public trials,” lawyers representing the media group said in an amicus filing.

But supporters of Proposition 8 said the trial “has the potential to become a media circus” in their appeal. “The record is already replete with evidence showing that any publicizing of support for Prop. 8 has inevitably led to harassment, economic reprisal, threats, and even physical violence.”