A constitutional amendment that seeks to define marriage as a heterosexual union was not heard in the North Carolina General Assembly's regular session, but proponents insist the measure will be considered during a special session in the fall.

House Majority Leader Paul Stam told the Associated Press last week that the marriage amendment could come up for consideration in the session's final week.

Instead, the measure remained shelved and its future will be decided during a special session which begins on September 12.

Gay rights groups said they put in over 4,000 calls in two days to help avert the action.

“The Charlotte and Raleigh HRC steering committees and Equality North Carolina made calls to volunteers, voters lists, and the HRC membership lists urging constituents to call and ask the legislator in their district to vote no on the bill,” said the Human Rights Campaign, the nation's largest gay rights advocate.

House speaker Thom Tillis earlier told the Citizen-Times that he believes the House will approve the amendment and send it to voters for their approval in 2012.

The proposed legislation was introduced in the Senate in February and in the House in April.

The Senate version explicitly bans other unions in addition to marriage, which might include civil unions and domestic partnerships, but the House version only covers marriage. Gay rights activists worry that the Senate version could outlaw domestic partner benefits currently offered by private sector employers.

Minnesota lawmakers have already approved a similar ballot question for next year.