LIVERMORE -- A group that hopes to stop BART from coming through downtown Livermore says it plans to file its petition Tuesday at City Hall.

At least 7,800 people who think future train tracks should stay along the freeway, with stations at Interstate 580-Isabel Avenue and I-580-Greenville Road, have signed the petition, said Valerie Raymond, a former Alameda County supervisor and unincorporated Livermore resident who is organizing the drive.

A minimum of about 4,700 valid signatures belonging to registered Livermore voters are needed to qualify the initiative for the November ballot.

"Basically, we're just trying to pull in all the stragglers at this point," Raymond said Thursday, noting that about 150 unpaid volunteers have been steadily gathering signatures outside the library, retail stores and other spots in town.

Even if the measure gets on the ballot and passes, it will not be enough to alter the chosen BART path, however.

Passage only would force Livermore council members to renege their support of the planned downtown route, essentially by requiring them to strengthen language in the city's general plan in favor of a freeway alignment.

Critics of the petitioners have argued that pursuing such a nonbinding initiative is a waste of taxpayer time and money that ultimately could kill any hope of a railway extension -- by sending the signal to BART that Livermore doesn't really want it.

Linda Jeffery Sailors, a former Dublin mayor and current Livermore resident who is involved with the petition, refuted accusations by some that her camp is trying to block BART-to-Livermore.

"We have been working for 30 years to get BART here and that's exactly what we want to do," she said.

Endorsed last year by Livermore's council and unanimously adopted by BART's board, the current $3.8 billion route would place an underground BART station downtown and another above-ground station along Vasco Road.

Though other alignments would appear to have lower price tags, the downtown-Vasco plan is the only one that's really fundable, according to supporters such as Livermore Mayor Marshall Kamena.

Neither the mayor nor the city attorney could be immediately reached for comment.

Only 1,515 residential units above and beyond the several thousand units already allowed in the general plan would be needed to meet federal funding requirements for housing near the Vasco and downtown stations, compared to the more than 6,000 units that would be needed for the Isabel-Greenville alternative.

Also, building near the environmentally sensitive Greenville site not only would require moving the urban growth boundary, but development there would face stiff opposition from water and wildlife agencies, city leaders say.

The arguments amount to "self-imposed restrictions" that could be worked out if city leaders really want to do so, Sailors said.

Deputy city clerk Toni Taber said city staff will conduct a rough count of the signatures to see if enough have been collected. From there, it will be up to the Alameda County Registrar of Voters to verify the signatures and certify the petition.

Contact Jeanine Benca at 925-847-2125.