New Hampshire voters are split almost evenly on a proposed state constitutional amendment that would prohibit an income tax in the Granite State, but are mostly united against a proposed repeal of gay marriage, according to the latest Granite State Poll.

The poll, sponsored by WMUR-TV and conducted by the University of New Hampshire Survey Center, found that 40 percent of voters would vote for an amendment that would prevent the state from enacting an income tax, while 41 percent would vote against it; 18 percent of voters are unsure. The amendment requires a two-thirds majority to pass.

Meanwhile, a majority of New Hampshire voters are against repealing a 2009 law that legalized same-sex marriage. Only 28 percent of voters support repealing the law; 51 percent strongly oppose a repeal, 10 percent somewhat oppose it, and 10 percent are neutral or don’t know.

The poll was conducted among 581 randomly selected adults between Aug. 1 and Aug. 12.