Updated

Overruling school officials, a Catholic bishop in Iowa said Monday he would not let a group that promotes equal rights for gays and lesbians present a college scholarship to an openly gay student during an upcoming award ceremony.

Bishop Martin Amos in Davenport said the Eychaner Foundation would not be allowed to present the Matthew Shepard Scholarship to Keaton Fuller during the May 20 ceremony at Prince of Peace Catholic School in Clinton, saying the group's support for gay rights conflicts with church doctrine.

The announcement comes after a school official signed a document last month that promised to let a representative of the foundation's scholarship committee present the award to Fuller.

In an open letter released Monday, Fuller said he's never felt so "invalidated and unaccepted" as he did when he heard that news last week. He said he and his family were asking the school to reverse its decision, and he launched an online petition Monday that was signed by hundreds of supporters within its first hours.

"This whole ordeal has been incredibly hurtful, and I am even sadder that this will be one of my last experiences to remember my high school years by," Fuller wrote.

The bishop's decision also stunned school officials, who had encouraged Fuller to apply for the award and wrote letters on his behalf.

Founded by Iowa businessman and gay rights activist Rich Eychaner, the Des Moines-based foundation has awarded more than 130 Matthew Shepard scholarships to graduating high school seniors who are gay, lesbian, bisexual or transgender since 2000. It is named for the gay Wyoming college student killed in 1998.

Citing his scholastic achievement and work fighting homophobia, the foundation chose Fuller this spring as one of three students for the gold scholarship, which is worth up to $40,000 over four years to attend one of Iowa's three public universities. Fuller, 18, plans to go to the University of Iowa.

Fuller is believed to be the first gay student at a Catholic high school to attend multiple school dances with a partner of the same sex, said foundation executive director Michael Bowser.

"We were very proud of him for that," he said.

Bowser said the group's award presentations are part of the scholarship process because they send a message of acceptance. He said three other Catholic schools had rejected presentations for scholarship recipients in prior years, but the group thought Prince of Peace would be the first to allow it, given the staff's support for Fuller.

Despite the school's promise, Amos told Fuller's parents last week that church policies on guest speakers would prohibit it, the Diocese of Davenport said in a statement. The policy says, "We cannot allow any one or any organization which promotes a position that is contrary to the teachings of the Catholic Church to present at a diocesan institution."

The diocese's statement congratulated Fuller for winning "the generous award," and said it would be announced by a school employee during the assembly.

School Board President Edward O'Neill said he was disappointed by the bishop's decision. He said Fuller was a talented student who was accepted by his peers after coming out years ago. He said Fuller had taken his boyfriend to prom over the weekend and other school dances without controversy.

O'Neill said board members were briefed on the scholarship last month, and they were aware a foundation representative planned to present the scholarship. No one raised an objection until the bishop got involved, he said.

"We preach tolerance and acceptance but then we turn around and we don't practice what we preach," he said. "If the bishop says we're not going to do it, I can voice my objection to it, but there's not a whole lot I can do."

Eychaner issued a statement saying he was shocked that the bishop believes the foundation's work clashes with church teachings, noting it promotes tolerance and fights bullying. And he said he was confused how the bishop found the award itself acceptable to be announced but not by its sponsor.