Leading gay rights groups are planning a protest against the prominent Atlanta law firm King & Spalding for taking up the legal defense of the Defense of Marriage Act.

In recent weeks, the Republican leadership of the U.S. House of Representatives retained Paul Clement to defend the law, which defines marriage as only a union between a man and a woman.

Clement, the head of King & Spalding's national appellate practice, will be paid $520 an hour for his representation. He once served as U.S. solicitor general for President George W. Bush.

The Obama administration has said it will no longer defend the law in court.

In a statement released this weekend, the Human Rights Campaign said it will be joined by Georgia Equality and other groups at a Tuesday news conference one block from King & Spalding's headquarters in Midtown.

The Human Rights Campaign, a lesbian, gay, bisexual and transgender civil rights group, said it wants to call attention to the law firm's "hypocrisy."

King & Spalding's website says the firm is committed to having the brightest and most diverse lawyers it can find, including members of the lesbian, gay, bisexual and transgender community. It notes that the Human Rights Campaign gave the firm a 95 out of a 100 corporate equality index rating the past four years and that domestic partner benefits are offered for same-sex couples.

"Firms are rightly judged on the cases they voluntarily take on, and history will not be kind to [King & Spalding's] decision to defend institutionalized discrimination," the Human Rights Campaign statement said. "The effect of K&S’s efforts, if successful, would ensure that the federal government is able to continue denying recognition to same-sex couples which includes Social Security survivor benefits, health care for spouses of government employees or even the ability for spouses to be buried together in veteran’s cemeteries."

Les Zuke, King & Spalding's director of communications, said the firm has no comment.

"As a matter of policy, the firm does not comment on client representation," he said.

In an editorial last week, the Los Angeles Times called the Defense of Marriage Act "wrongheaded," but urged gay rights groups to refrain from attacking lawyers who defend it.

"The tradition of lawyers defending unpopular or controversial clients is an honorable one," the newspaper said.