The Tennessee Natural Marriage Defense Act attempts to defy the U.S. Supreme Court's ruling on marriage equality, declaring that the only valid marriage in the state is one between a man and a woman.

A bill making its way through the Tennessee state legislature aims to roll back marriage equality in the Volunteer State. But LGBT advocates say the legislation is an unconstitutional attempt to overrule the U.S. Supreme Court.

Tennessee Republican Rep. Mark Pody, who claims God has called him to stop same-sex marriages, introduced House Bill 1412, the Tennessee Natural Marriage Defense Act, last September. At the same time, Sen. Mae Beavers, also a Republican, introduced companion legislation in the Senate.

As written, the bill seeks to declare it "the policy of Tennessee to defend natural marriage between one man and one woman regardless of any court decision to the contrary." It requires state officials, including the attorney general, to "defend any state or local government official from any lawsuit" arising from an official's refusal to marry a same-sex couple. The bill also seeks to prevent state and local agencies from implementing any punishment for those violating the Supreme Court's June 2015 ruling that mandated legal marriage equality nationwide.

Both chambers passed respective versions of the bills on first consideration, and several additional sponsors have signed on to each version since its introduction last year. The legislation is due to be heard in the House Civil Justice Subcommittee on Wednesday. Three "consideration" votes in each chamber are necessary for final passage of a bill.

The Human Rights Campaign issued a scathing statement Tuesday, blasting the legislation as a disgraceful attempt to eliminate marriage equality in the state.

“The Supreme Court of the United States has unequivocally settled the issue once and for all by making clear that loving and committed same-sex couples have the fundamental right to marry,” said HRC legal director Sarah Warbelow in a statement. “This legislation is thoroughly unconstitutional, and it would no doubt cost taxpayers significantly in a vain, injudicious attempt to undermine marriage equality for LGBT Tennesseans.”

The state's LGBT equality organization joined HRC in its condemnation of the bill. “This outrageous attack on LGBT Tennessee families is reckless and appalling,” Chris Sanders of the Tennessee Equality Project said in the HRC statement. "Attempting to undermine the fact that marriage equality is the law of the land is a stain on Tennessee's reputation, an unacceptable risk to our state budget, and a chilling message to LGBT people in Tennessee. Fair-minded people from Memphis to Mountain City are speaking up to say that this extremist attack on equality will not be tolerated. The time for allies to join us is now.”

Indeed, the financial impact that Sanders referenced is noted in the fiscal notes attached to the bill on the state's website. If passed, the so-called Natural Marriage Defense Act would "decrease state revenue" by as much as $2 billion, according to the fiscal summary produced by the state legislature.

"The provisions of the bill could jeopardize federal funding if it is determined the state is noncompliant with federal law," that summary states. Citizens in a legal same-sex marriage, who would otherwise be eligible to receive certain benefits available to low-income residents, such as the state's version of Medicaid, TennCare, and food stamps, could be denied those benefits under the proposed law. That would imperil the sizable federal funding Tennessee receives to support these safety net programs, the fiscal summary explains.

The legislation is a flagrant attempt to defy the U.S. Supreme Court's historic 2015 ruling, said several of the couples who were involved in the case out of Tennessee that reached the Supreme Court and was decided in June under the consolidated name Obergefell v. Hodges.

“We are horrified to learn of this new bill,” said Johno Espejo and Matthew Mansell, one of the plaintiff couples in Tanco v. Haslam, the Tennessee case that was included in the Obergefell decision. “This abhorrent bill is an attempt to unconstitutionally circumvent the law of the land and to specifically single out and harm a minority group. We became plaintiffs in our case precisely in order to fight this type of prejudice being waged against our marriage and our family. This bill is wrong and should be voted down.”