The Expo light-rail line runs from downtown Los Angeles to Culver City. Phase two of the rail line’s expansion would take the trains all the way to Santa Monica Beach, but that’s not happening without a fight.

Proponents of the downtown-to-Santa Monica Expo line gathered at a construction site in Palms on Monday to make their case in the court of public opinion.

They contend that work on the rail line needs to continue, this after filing opposition to a motion to stop construction on the project until the California Supreme Court rules on a lawsuit brought by Neighbors for Smart Rail.

“I’m hoping the court will see through this as a stunt to try to kill this project,” said LA County Supervisor Zev Yaroslavsky.

Easing traffic and keeping jobs are the two main reasons elected officials and the Expo Construction Authority say work on phase two of the train line cannot stop. The project’s first phase, which runs from Downtown to Culver City, began running in June.

“For decades, this train has been planned as a relief valve for the I-10. There is a huge amount of pent up demand, not only in Santa Monica but in all the communities that are along the line,” said Santa Monica Mayor Richard Bloom.

The Expo line supporters say a one year stay would cost at least $90 million and hit construction workers hard.

“A $90 million delay wastes the money of the LA County taxpayers. This delay will also cause a job loss, a loss of up to 4,000 jobs,” said Ron Miller, executive secretary of the Los Angeles Orange County Building and Construction Trades Council.

Neighbors for Smart Rail, a non-profit organization supported by some west-side homeowners associations, says it requested a stay when Expo line construction didn’t stop after it filed an appeal with the California Supreme Court.

Yaroslavsky said it is “just crazy” to stop the project “mid-stream.”

“We don’t need to stop the project in order to resolve the legal issues,” he said.

In an email, NFSR President Terri Tippit said the organization is not against the line but doesn’t want it to be built at street level where the trains could hit pedestrians, threaten emergency response times and further congest I-10 access roads. Their opponents say that’s unrealistic.

“What we will not do and cannot do, because it’s physically impossible and financially impossible, is we're not going to build a subway under Palms or under Cheviot Hills. We're not going to put this whole damn thing underground,” Yaroslavsky said.

The Supreme Court is expected to make a decision on the stay in a matter of weeks. Both sides say they are confident they will ultimately win.

“This train here has the opportunity, when it is built, to take us not just between downtown and the Westside, it has the opportunity to take us into the future of Los Angeles; a future with traffic relief and a future with jobs and economic revitalization,” said Mike Bonin, chief of staff for LA City Councilman Bill Rosendahl.

Elected officials say if the Supreme Court rules in favor of the second phase of the Expo line construction, it should be completed in 2015.

NOTE: An earlier version of this story had an incorrect spelling for Mike Bonin's last name. The story has been corrected.