A majority of Americans oppose the Defense of Marriage Act (DOMA) and the Republican decision to defend it, a new poll found.

The poll released Tuesday by the Human Rights Campaign (HRC), the nation's largest gay rights advocate, found 51 percent of voters oppose the 1996 law that defines marriage as a heterosexual union for federal agencies. Thirty-four percent of respondents said they support the Clinton-era law.

Last week, House Speaker John Boehner decided he would defend the law in court now that President Barack Obama has said he believes parts of it are unconstitutional and has directed his administration to stop defending the statute.

“Additionally, when read statements for and against defending DOMA in court, 54 percent of voters oppose the House Republicans' intervention, while only 32 percent support it,” HRC said in announcing the survey's results.

A majority of respondents said they supported giving gay and lesbian couples many of the federal marriage benefits being blocked by the law, including Social Security benefits and joint tax filling.

Legislation that would repeal DOMA is expected to be introduced in the House and Senate on Wednesday.