A federal appeals court has lifted the order banning public prayer at a Texas high school graduation Saturday.

The reversal comes on the heels of increasing criticism of a federal judge's earlier ruling that agreed with the parents of one graduating student that religious expression during the ceremony at Medina Valley Independent School District would cause "irreparable harm" to their son.

The 5th U.S. Circuit Court of Appeals thought differently, reversing the judge's ruling Friday and allowing students to say the word "amen" and invite the audience to pray during the ceremony.

"This is a complete victory for religious freedom and for Angela," said Kelly Shackelford, president/CEO of Liberty Institute, which had represented class valedictorian Angela Hildenbrand in the appeal. "We are thrilled that she will be able to give her prayer without censorship in her valedictorian speech tomorrow night. No citizen has the right to ask the government to bind and gag the free speech of another citizen."

Chief U.S. District Judge Fred Biery's initial ban had been denounced as an "activist decision" by U.S. Sen. John Cornyn, R-Texas, who called it "exactly the wrong civics lesson to teach to the class of 2011."

Biery had ruled Thursday in favor of Christa and Danny Schultz, who sued to block such religious expressions at their son's graduation. Among the words or phrases Biery had banned were: “join in prayer,” “bow their heads,” “amen,” and “prayer.”

He also ordered the school district to remove the terms “invocation” and “benediction” from the graduation program, in favor of "opening remarks" and "closing remarks."

Texas Attorney General Greg Abbott responded by voicing support for the school district in its appeal.

“Part of this goes to the very heart of the unraveling of moral values in this country,” Abbott told Fox News Radio, saying the judge wanted to turn school administrators into “speech police.”

“I’ve never seen such a restriction on speech issued by a court or the government,” Abbott told Fox News Radio. “It seems like a trampling of the First Amendment rather than protecting the First Amendment.”

Biery's ruling infuriated religious activists, like the AGAPE Movement, a Christian group based in Wichita Falls, Texas, which had said Friday it would travel to the school in Castroville for a peaceful protest if the ban wasn't reversed, according to the San Antonio-Express News.

The family's suit was being backed by the Washington-based Americans United for Separation of Church and State.

Fox News Radio's Todd Starnes and The Associated Press contributed to this report