SALEM, Ore. (AP) -- The effort by some social conservative and church groups to overturn two gay rights laws passed by the 2007 Oregon Legislature may be struggling.

This is the final weekend for those groups to gather signatures to derail a domestic partnership law giving same-sex couples most of the state benefits of marriage along with another new law banning discrimination based on sexual orientation.

One of the organizers of the petition drive says interest in the issue has been "exploding" in recent days. But a former state senator who is acting as spokeswoman for the loosely organized coalition of petitioners is less optimistic.

Marylin Shannon says petitioners have gathered about 40,000 signatures for each of the two referrals. At least 25,000 additional signatures will need to be collected in the coming days in case some are not invalid.