Fresno County supervisors plan to revisit high-speed rail this month, a sign that they may be looking to scrap support for the project.

While the supervisors have no decision-making power over the proposed rail system, which is expected to break ground early next year, withdrawing their endorsement would be a symbolic blow to an effort that's struggling to maintain popularity.

Fresno County remains one of just two San Joaquin Valley counties along the line that is on record backing high-speed rail and, as the largest, has power to sway public opinion.

"It's very significant to have as much local support as possible," said Tom Richards, a Fresno developer and vice chairman of the state High-Speed Rail Authority board. He said Fresno County's reversal would be a disappointment.

The rail authority is proposing a 520-mile system that would run trains between San Francisco and Los Angeles, through Fresno, in just 21/2 hours.

The project, however, is drawing criticism for its cost and the course of the tracks.

This week, Supervisor Judy Case called for a discussion of high-speed rail at the next board meeting March 27. While Case stopped short of saying she wants to pull support for the project, she expressed doubts.

"Currently, they're in a full-speed-ahead mode, and I think they need to slow that up and take care of the details and the criticism," she said.

The Board of Supervisors passed a resolution committing support for the project in 2007 and, in 2010, renewed that commitment in a letter to the rail authority with a 5-0 vote.

But Case noted that the terms of the project have since evolved, including the price tag and route plan, and said it was the board's responsibility to take another look.

In November, the rail authority increased the cost estimate from $45 million to $98 billion. That's left some wondering where the additional money will come from. The route also has been set for west of the Highway 99 corridor in Kings County, angering some farmers who would see their land split by tracks.

Supervisors Phil Larson and Debbie Poochigian have also begun to air criticism. Neither would commit, however, on whether the board should change its stance.

Supervisor Henry Perea, a longtime advocate of rail, said rescinding support is a bad idea. He said it would only undermine the county's bid to locate an economically valuable rail maintenance station in Fresno County.

"The go or no-go decision about high-speed rail rests at a much higher level of pay grade. We shouldn't touch it," he said. "We don't want to send the wrong signal to the authority and lose the opportunity to have the maintenance facility and the jobs that come with it."

The other county that has endorsed the rail project is Merced.

Perea said Merced County would likely win the maintenance yard if Fresno County withdrew its backing, just as Merced got a University of California campus instead of Fresno.

"I don't want this board to be responsible for the next UC Merced situation," Perea said.

The Board of Supervisors is not likely to withdraw its endorsement at the next meeting -- the agenda item is yet to be finalized -- but it could direct that a new resolution be drafted for follow-up consideration. The board also could order a letter to be written, expressing concerns.

Richards, with the rail authority, said he hopes that supervisors will wait for a new business report on the rail project, due out at the end of the month, before changing sides.

"There's too much valuable information in the document that will be necessary to have reviewed to make a decision," he said. "We've worked very hard to address concerns."