The state Board of Elections announced Tuesday the Maryland Marriage Alliance, which opposes the law, had gathered enough valid signatures for certification, The Baltimore Sun reported. The group submitted more than 160,000 signatures, but the board stopped the count after validating 109,313.
Both the alliance and Marylanders for Marriage Equality say they are ready for the battle. Dereck McCoy, head of the alliance, said the group is "excited" about the success of its petition drive.
"Our base is fired up," Kevin Nix, head of the pro-gay marriage group, told the Sun. "Momentum is with us."
Marylanders for Marriage Equality has begun releasing material aimed at black voters, a group historically hostile to gay rights issues. An Internet ad features blacks giving their reasons for supporting gay marriage.
Polls have shown President Obama's recent announcement of support for gay marriage has also shifted opinion among blacks. NAACP head Julian Bond also released a statement Tuesday supporting gay marriage and saying Maryland voters will be making their decision based on the law.