Opponents of the Houston Equal Rights Ordinance failed to gather enough valid signatures to put the measure before voters, city officials announced on Monday.

"There are simply too many documents with irregularities and problems to overlook. The petition is simply invalid. There is no other conclusion," City Attorney David Feldman announced on Monday. (Watch above)

HERO opponents submitted 5,199 pages of signatures, but after the city's 30-day review process, just 2,449 qualified for consideration, Feldman said. That left opponents with 15,259 signatures; they needed 17,269.

Mayor Annise Parker said she expects opponents to challenge that decision in court. Because of that, she's delaying implementation of HERO "not indefinitely, but certainly to allow some of these issues to work their way out."

"I fully expect, because we have invalidated the petitions, that the petitioners will head to the courthouse," Parker said. "I am confident that the courts will agree the with out strict interpretation of rules set out in the charter and that the courts will protect the integrity of our petition process. But it will take however long it takes for that to happen."

Parker, who last month blasted the petition effort as a "strange obsession," said HERO supporters would have won a public referendum on the anti-discrimination measure.

"I have been confident since we started down this path that I fully expected it to end up on a ballot and that we would win. If it does not end up on a ballot, it saves the city a significant amount of money and efforts of mounting a legal campaign," Parker said.

Parker said if a legal challenge overturned the city's petition review, that would likely push a public vote back to November 2015.

"They could choose not to challenge it," Parker said of opponents.

HERO, the city's first comprehensive equal rights ordinance, passed the City Council in May. The ordinance protects a broad range of categories – including sex, race, ethnicity, marital status, religion, sexual orientation, genetic information, gender identity and pregnancy – from discrimination in city employment and services, housing, public accommodations, and public and private employment.

[video via HTV]