By Duncan Mackay

Peter Vidmar. Photo: www.zimbio.comPeter Vidmar tonight resigned as Chef de Mission of the United States team for next year's Olympics in London only a week after being appointed following a series of damaging allegations over his opposition to same-sex marriage.

Vidmar's decision to step down follows reports in the Chicago Tribune that he participated in two anti-gay marriage demonstrations and donated $2,000 (£1,222) for the successful 2008 Proposition 8ballot initiative in California defining marriage as between a man and a woman.

The proposition overturned a California Supreme Court ruling that permitted same-sex marriage.

Vidmar, who won two gymnastics gold medals at the 1984 Olympics in Los Angeles, claimed his opposition to same-sex marriage comes from his religious beliefs as a Mormon.

"The Church wanted to take a stand on the issue, and they invited their members to take a stand," he told the Chicago Tribune.

"I chose to be involved."

Among those to criticise Vidmar's decision to support the opposition to same-sex marriage was Aimee Mullins, the Chef de Mission of the US Paralympic team for London 2012, who said she was "concerned and deeply saddened" about his past actions.

"The Olympic Movement is about promoting equity for all," she said.

The United States Olympic Committee (USOC) claimed that they were unaware of Vidmar's views before they appointed him and initially supported his right to express his views on the controversial issue.

But they have now accepted his resignation.

"Peter is respected the world-over for his dedication and commitment to the Olympic movement and is rightly considered one of America's great Olympic champions," said USOC chief executive Scott Blackmun.

"I believe Peter would have served our athletes well, but given the nature of this issue, I certainly respect his decision to resign.

"As we look toward London 2012 and the selection of Peter's replacement, we'll do so with the sole intent of showcasing America's best and brightest stars and the inspirational story that each member of our Olympic team has to share."

Vidmar said he had decided to step down because he did not want to distract the athletes preparations in the build-up to London 2012.

"I have dedicated my life to the Olympic Movement and the ideals of excellence, friendship and respect," he said.

"I wish that my personal religious beliefs would not have become a distraction from the amazing things that are happening in the Olympic Movement in the United States.

"I simply cannot have my presence become a detriment to the US Olympic family. I hope that by stepping aside, the athletes and their stories will rightly take centre stage."

Contacat the writer of this story at