With the deadline six weeks away, organizers of an initiative to repeal the Sonoma-Marin Area Rail Transit sales tax have about half the signatures they believe are needed to put a measure on the ballot.
Clay Mitchell of Windsor, co-chairman of Repeal SMART, said about 100 volunteers have returned petitions, containing 7,500 signatures.
Mitchell said an additional 119 volunteers have petitions that have not been turned in.
"I don't have a count at this point; I couldn't even guess," Mitchell said. "It is a gargantuan task."
RepealSMART believes that 15,000 signatures are necessary, citing the threshold set by Proposition 218, a measure passed by voters in 1996 that required two-thirds votes on most tax measures and set up an initiative process to repeal existing taxes.
Two other state election laws, however, have formulas that would set the thresholds at 30,000 or 39,000 signatures.
Mitchell acknowledged Friday that his group would not be able to meet those higher thresholds.
SMART supporters said they aren't surprised.
"I didn't expect the repeal people to be successful," said Windsor Mayor Debora Fudge, a member of the SMART board. "Everywhere I go I have heard support."
RepealSMART has been circulating petitions since late September in an effort to put a measure on the ballot next year to overturn Measure Q, the quarter-cent sales tax that was approved by 70 percent of Sonoma and Marin voters in November 2008.