Gay groups are protesting the choice of Reverend Rick Warren to deliver the invocation at President-elect Barack Obama's inauguration.

Human Rights Campaign, the nation's largest advocate for gay and lesbian rights, issued a statement on Wednesday calling the choice “disrespectful” to gay and lesbian Americans.

“We feel a deep level of disrespect when one of the architects and promoters of an anti-gay agenda is given the prominence and the pulpit of your historic nomination,” HRC President Joe Solmonese said.

The Reverend Rick Warren is the spiritual leader of millions and heads the prominent evangelical Saddleback Church in Southern California.

Warren and Obama first met in 2006 at a Saddleback AIDS forum where the president-elect challenged him on preaching against contraception.

A prominent leader in the evangelical movement, Warren supports the outlawing of abortion in all cases and is a staunch gay rights opponent.

“Rick Warren has not sat on the sidelines in the fight for basic equality and fairness,” Solmonese said. “In fact, Rev. Warren spoke out vocally in support of Proposition 8 [the gay marriage ban] in California saying: 'There is no need to change the universal, historical definition of marriage to appease 2 percent of our population ... This is not a political issue – it is a moral issue that God has spoken clearly about.' Furthermore, he continues to misrepresent marriage equality as silencing his religious views.”

Warren, however, has gone further by likening gay marriage to an incestuous relationship, pedophilia and even polygamy.

In an interview with editor Steven Waldman, Warren said: “I'm opposed to having a brother and sister be together and call that marriage. I'm opposed to an older guy marrying a child and calling that a marriage. I'm opposed to one guy having multiple wives and calling that marriage.”

“Do you think, though, that they are equivalent to having gays getting married?” Waldman asked.

“Oh, I do,” Warren answered.

Solmonese urged Obama to reconsider his decision.