While a majority of North Carolinians continue to oppose gay marriage, opposition is on the decline.

Less than two years after voters approved a constitutional amendment defining marriage as a heterosexual union by a 22 point margin, opposition to marriage equality has dropped 9 percentage points.

According to a Public Policy Polling survey released Thursday, 40 percent of respondents said that they support allowing gay couples to marry, while 53 percent remain opposed.

However, a majority (62%) of respondents support recognizing the unions of gay couples with either marriage (36%) or civil unions (26%). Only 34 percent said there should be no legal recognition of a gay couple's relationship.

The findings were released a day after the ACLU of North Carolina filed a lawsuit in federal court challenging the constitutionality of the state's marriage ban.

(Related: Three married couples challenge North Carolina's gay marriage ban.)