Inclusion of gay and lesbian immigration rights are being blamed for tripping up comprehensive immigration reform legislation currently before Congress.

On Thursday, California Representative Michael Honda introduced the Reuniting Families Act, a comprehensive immigration reform package that includes New York Representative Jerry Nadler's Uniting American Families Act (UAFA), which would allow gay Americans to sponsor an immigrant partner for citizenship.

Introduction of the UAFA in the House trails the Senate version, where hearings began on Wednesday.

But even before the hearings started, social conservatives were howling over the fact that the UAFA was included in the reform package, and drove one major partner to withdraw its support from the House version that knits the two bills together.

In a letter sent to Honda, the United States Conference of Catholic Bishops, a major ally in securing immigration reform, called the gay provisions “contrary” to its position on marriage. The new bills address gay inequities by striking out language that reefers to married spouses in favor of the more clinical – and socially contentious – term “permanent partners.”

“[Including the gay provisions in the immigration bill] would erode the institution of marriage and family by according marriage like benefits to same-sex relationships, a position that is contrary to the very nature of marriage, which pre-dates the church and the state,” the bishops wrote.

Another ally, the National Hispanic Christian Leadership Conference, decried the gay provisions, calling their inclusion a “slap in the face to those of us who have fought for years for immigration reform,” Reverend Samuel Rodriguez told Politico.com.

The issue is a powerful one for gay activists who recently formed a group specifically to lobby on behalf of binational gay and lesbian couples.

A spokesman for the three-year-old Immigration Equality said the group was “disappointed” that the Senate bill did not include the gay provisions but insisted Senator Pat Leahy, chairman of the Senate Judiciary Committee charged with overseeing the immigration hearings, was committed to passage of the UAFA.

“Senator Leahy's hearings earlier this week sent a clear and unmistakable message that he intends to continue working hard for our inclusion in comprehensive immigration reform,” Immigration Equality Director of Communications Steve Ralls told On Top Magazine.

“Three of the four bills currently pending in Congress include lesbian and gay couples, and we're confident that as immigration reform moves forward, we will be part of the effort to fix our country's broken immigration system,” Ralls added.

But even gay rights backers admit they'll have a steep incline to overcome.

“You got two very tough issues – the rights of same-sex couples and immigration,” openly gay Congressman Barney Frank, a Democrat from Massachusetts, told the Washington Blade. “You put them in the same bill, and it becomes impossible. We just don't have the votes for it.”