Support for a constitutional amendment in North Carolina which would ban gay marriage continues to decline, a poll has found.

Voters will decide on Amendment One during North Carolina's May 8 primary. The constitutional amendment would bar the state from recognizing the relationships of gay and lesbian couples with marriage, civil unions and possibly domestic partnerships.

A Public Polling Policy poll released Tuesday of 1,139 likely voters found support for the ban at its lowest since October.

According to the poll, 54 percent of voters support the amendment, while 40 remain opposed. The pollster's first poll gave the amendment a 27 point advantage (61 – 34%), which has now been cut by nearly half.

“There is some reason to think a huge upset in two weeks is within the realm of possibility,” PPP's Tom Jensen said in reporting the group's findings.

“When voters are informed that the proposed amendment would preclude both marriage and civil unions for gay couples only 38% continue to support it with 46% in opposition. Voters obviously will be more tuned into the amendment debate over the final two weeks of the campaign than they have been to date, particularly as the against side's TV ads hit the air, and it seems quite possible that as voters become more and more informed about the amendment they will continue to move more and more against it.”

(Related: Opponents of North Carolina gay marriage ban release TV ads.)

Added Dean Debnam, president of PPP: “Passage of the marriage amendment is looking like less and less of a sure thing. The more voters learn about it the less inclined they are to support it.”