Two signature-gathering efforts to place a referendum on the ballot to eliminate Seattle's mandated new $15-an-hour minimum wage have failed.

Needing 16,510 voters' signatures to make the ballot, an effort by business group Forward Seattle qualified 14,818 signatures out of 18,929 obtained. Save Our Choice fared even worse, garnering only 455 valid signatures.

In June, the Seattle City Council voted unanimously to raise the minimum wage in the city to $15 an hour. The measure calls for businesses with 500 or more employees to match the minimum wage within three years (four if they offer health insurance). Businesses with fewer than 500 employees have seven years to reach the mandate.