OAKLAND -- BART's two largest labor unions on Tuesday turned to the courts in a push to end their contract stalemate with the transit agency over a disputed family leave provision.

The Amalgamated Transit and Service Employees International unions expanded their allegations of unfair labor practices against BART's elected board and asked the Alameda County Superior Court to impose the contract -- with paid family leave -- on the agency.

The lawsuit is the unions' answer to the BART board's characterization of the paid leave provision as a clerical mistake followed by its Nov. 21 vote to condition contract approval on a new union vote for a revised deal without the perk.

Kerianne Steele, attorney for the Service Employees International Union Local 1021 representing BART workers, holds a stack of legal papers as she speaks
Kerianne Steele, attorney for the Service Employees International Union Local 1021 representing BART workers, holds a stack of legal papers as she speaks in front of the Superior Court of California County of Alameda courthouse in Oakland on Dec. 3, 2013. (Jane Tyska/Staff)

"A deal is a deal," echoed several representatives of the two unions on the courthouse steps Tuesday morning.

"BART cannot repudiate a total package or refuse to ratify for an improper purpose or without good cause," SEIU attorney Kerianne Steele said. "BART will not be able to show they have good cause to back away."

BART board Vice President Joel Keller, of Antioch, defended the board's actions as fiscally prudent and legal.

The disputed provision would give workers six weeks of full pay for approved leave to care for a baby or sick or injured family member in addition to their vacation and sick leave.

BART estimates the perk would cost an additional $6 million to $44 million over the life of the four-year, $67 million contract, depending on how many people take it.

Keller, who is expected to become BART board chairman, called the unions' lawsuit a "Hail Mary," a term used when an out-of-time football player hurls the ball toward the end zone and prays for a miracle.

"When you throw a Hail Mary pass, if it's caught, you get a touchdown," Keller said. "If it isn't caught, in this case, you can tell your members, 'we tried.'"

The unions filed the initial unfair labor practices lawsuit against BART in June, alleging numerous violations of state law mandating that all parties negotiate in good faith and take all reasonable efforts to reach an agreement.

Both sides anticipated the lawsuit would go away after BART and its labor negotiators reached a tentative deal Oct. 21 and members of both unions ratified it.

But the BART board's recent refusal to ratify the contract unless the unions ditch the family leave perk sent the labor leaders back into the courtroom.

It is "totally unprecedented for an employer, after extensive negotiations and where they have signed off on (individual tentative agreements), to later come back and say, 'Oh, we made a mistake,'" said veteran labor attorney and Boalt law school professor David Rosenfeld, whose firm represents SEIU Local 1021.

Whether a judge will ultimately decide the BART labor dispute is an open question.

Litigation costs both sides money, and BART workers cannot collect their promised raises while the new contract is in limbo.

And the court could simply order both sides back to the bargaining table.

Several union representatives during comments Tuesday pointedly left open the door for an out-of-court settlement, saying they were open to "meaningful talks." So far, there is no talk of another strike.

"There are ways we could implement the (family leave provision) that would be acceptable to both parties," SEIU counsel Steele said.

For Keller's part, he insists the board is highly unlikely to add even a single penny to the contract. He appears to prefer his odds in court.

"I'm not aware of any case where a member of the judiciary has told an elected board, 'You have to accept this unratified contract no matter what it costs,'" Keller said. "And if it is forced upon us, it could result in a fare increase."

Contact Lisa Vorderbrueggen at 925-945-4773. Follow her at Twitter.com/lvorderbrueggen.