Opponents of Sonoma-Marin Area Rail Transit's plans are recruiting paid signature-gatherers in a last-ditch effort to get a measure on the November ballot to overturn the commute line's sales tax.

RepealSMART organizers also said Thursday they are intent on gathering 40,000 signatures by Jan. 27 to force SMART directors to set the election.

"We would rather the money go to people locally than spend the money to fight this in court," said Clay Mitchell of Windsor, co-chairman of the repeal effort.

SMART's opponents believe that only 15,000 signatures are necessary to qualify the measure, using a threshold set by Proposition 218, a measure passed by voters in 1996 that set up an initiative process to overturn existing taxes.

SMART officials, however, are relying on the Secretary of State's advice to follow a state election law that uses a different formula, which would require 39,000 signatures.

Organizers of the repeal campaign believe they will reach the 15,000 mark, Mitchell said, but by paying $1 per signature may possibly collect 40,000 signatures, giving SMART no choice but to set the election.

RepealSMART has relied on 250 volunteers to circulate petitions since late September. Mitchell said they are still trying to determine how many signatures they have gathered so far.

Supporters of SMART on Thursday called it a sign of desperation and a lack of community support for the repeal campaign.

"It is a sign of urgency and unease that they will not make their goal," said Jack Swearengen, chairman of Friends of SMART and of a broader group, the SMART Riders Coalition, made up of business, labor and transportation advocates.

RepealSMART is circulating petitions in an effort to place a measure on the November ballot to repeal the quarter-cent sales tax, which voters approved in Sonoma and Marin counties by 70 percent in November 2008.

The opponents argue SMART has downsized the plan to a point that it is no longer what was promised voters and would not draw enough ridership to relieve traffic and reduce emissions.

SMART has sold construction bonds and awarded a contract for the first rail segment, from Guerneville Road in Santa Rosa to downtown San Rafael, but it is 38.5 miles instead of the 70 miles originally planned and service will start one to two years behind schedule.

Extending the line to Cloverdale and to Larkspur is still planned as additional funds become available.

The quarter-cent sales tax is the main source of funding for the project, along with other local, regional, state and federal funds.

To recruit people to gather signatures, RepealSMART sent e-mails to the thousands of registered voters in Sonoma and Marin counties who included their e-mail addresses in their registration, Mitchell said.

So far, the group has raised about $20,000, all in small donations averaging about $100, Mitchell said. He and co-chair John Parnell of Novato will dip into their own pockets to make up the difference, if necessary, he said.