Lesbian and gay rights advocates in America have reacted with fury to the announcement that Rick Warren has been asked to deliver the Invocation at the Presidential Inauguration next month.

President-elect Obama will take the oath of office on January 20th as part of a huge ceremony and celebrations in Washington DC.

At least one million people are expected to attend and billions across the world will watch on TV.

Mr Warren, who is the pastor of one of the largest churches in California, publicly backed Proposition 8, a ballot measure that denies same-sex couples the right to marry.

It passed on November 4th but is subject to legal challenges about its legitimacy.

Campaigner Leah McElrath said in an opinion piece for the Huffington Post:

“Progressive groups are decrying the choice of Rick Warren to deliver the Invocation at the Presidential Inauguration as “disappointing” – but it is far more than that.

“It is an act of spiritual violence against lesbian and gay American citizens and a profound betrayal of the philosophy of inclusion and unity espoused by President-elect Obama.”

While Mr Warren will say a prayer at the ceremony, the oath of office is the responsibility of the Chief Justice of the US Supreme Court.

Human Rights Campaign, America’s largest LGBT advocacy group was also unhappy about the choice of Mr Warren.

“Your invitation to Reverend Rick Warren to deliver the invocation at your inauguration is a genuine blow to LGBT Americans,” HRC president Joe Solomonese said in a letter to Barack Obama.

“Our loss in California over the passage of Proposition 8 which stripped loving, committed same-sex couples of their given legal right to marry is the greatest loss our community has faced in 40 years.

“And by inviting Rick Warren to your inauguration, you have tarnished the view that gay, lesbian, bisexual and transgender Americans have a place at your table.

“Rick Warren has not sat on the sidelines in the fight for basic equality and fairness.

“In fact, Rev. Warren spoke out vocally in support of Prop 8 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. This was a lie during the battle over Proposition 8, and it’s a lie today.

“Rev. Warren has often played the role of general in the cultural war waged against LGBT Americans, many of whom also share a strong tradition of religion and faith.”

Barack Obama does not support same-sex marriage, but is in favour of full equal rights for lesbian and gay couples through civil unions.

In August, during the Presidential campaign, then-Senator Obama and his Republican opponent Senator John McCain made a joint appearance before 2,800 evangelicals at Mr Warren’s mega-church in California.

The discussion was later broadcast on CNN.

Asked about marriage, Obama said: “I believe that marriage is the union between a man and a woman.

“Now, for me as a Christian, it’s also a sacred union. God’s in the mix.”