A strike by hundreds of Fairfax Connector workers, impacting the commutes of an estimated 30,000 Northern Virginia bus riders, illustrates the growing fight over the privatization of public services.

The strike also foreshadows the likelihood of a battle over plans to privatize operations of Phase 2 of Metro’s Silver Line.

Nearly 600 Fairfax Connector workers went on strike Thursday. They joined about 130 Metrobus workers at the Cinder Bed Road Metrobus garage in Lorton, who have been on strike since Oct. 24, affecting an estimated 8,500 riders.

All the workers are employed by Transdev, a multinational transit provider that both Fairfax County and Metro have contracted with to provide service. The workers are all represented by local chapters of Amalgamated Transit Union, the nation’s largest transportation workers guild.

The workers are seeking better pay and benefits, including annual raises. In the case of the Metrobus workers, they say they are seeking wages comparable to those of workers employed directly by Metro for doing the same job.

But for Metro — and local governments — privatization allows them to save money by avoiding expensive costs such as pensions and health care. They pay contractors a set amount to provide a particular service.

It’s this deeper philosophical disagreement of whether public transit should be privatized that both sides say has crippled bus service in Northern Virginia and created what could be a protracted fight.

ATU International President John Costa said his union is fighting for “the future of public transportation in our region.”

The union maintains that private companies cut corners, leading to unsafe conditions for drivers and riders and ultimately causes service to decline.

Transdev North America operates in 200 cities and communities in the United States and Canada, offering a variety of modes of transportation, including bus, paratransit, streetcar and shuttles. Michael Setzer, president of its transit division, said the company couldn’t remain in business if they weren’t good at what they do — including being able to attract and retain quality workers and negotiate with unions.

“We’ve gotten pretty good at this,” Setzer said. “It’s frustrating to me that we can’t resolve this at the bargaining table.”

Setzer said the union is commingling vastly different salary and benefit issues at the Metrobus garage and Fairfax Connector to pressure Metro to stop any further privatization of its facilities.

Metro outsources a number of its services, but the Lorton garage is the only segment of its main bus or rail service that has been outsourced. However, Metro General Manager Paul J. Wiedefeld has discussed plans to privatize operations of the second phase of the Silver Line when the transit agency takes possession. The line will extend Metro to Dulles International Airport and into Loudoun County. The union is strongly opposed to the idea.

“It looks to me that they have decided that this is the time and place where they’re making a stand,” Setzer said.

Metro has been reticent to engage the union in the broader fight. When it built the Cinder Bed Road facility and outsourced operations, it was up front about its desire to save money at a time when operating costs had ballooned and fare revenue was down.

Metro spokesman Dan Stessel declined Thursday to comment on what role privatization has played in the current labor disputes.

Fairfax County officials expressed anger and frustration with both strikes, calling on Metro to quell tensions at the Cinder Bed Road garage that have now spread to the county’s Connector bus system.

Sharon Bulova, chair of the county’s Board of Supervisors, said she is calling a special board meeting next week to decide how the county can pressure Transdev into reaching an agreement with Connector workers.

Bulova (D) noted that the county’s contract with Transdev allows Fairfax to fine the contractor for every day that a strike continues and, then, seek damages for any loss in ridership resulting from a work stoppage.

“The only way that Fairfax County can have an impact on this is to put pressure on Transdev to work it out, and one of the ways would be to impose some of the fees that we’re able to assess,” Bulova said.

Bulova also said that the county is reconsidering its support for Metro’s use of a private contractor for portions of the second phase of the Silver Line rail extension — a move that would place a major stakeholder in that project at odds with the transportation agency it partially funds. Half of the six stations in Phase 2 are in Fairfax. All of Phase 1 of the Silver Line is in the county.

She said she is worried that the tensions at the Cinder Bed garage — where lower-paid Transdev employees work side-by-side with Metro employees with better union contracts — will spread to the Silver Line, potentially leading to more work stoppages.

“Fairfax initially was supportive of privatization of some Metro service,” including at the Cinder Bed site before it opened last year, she said. “Looking at the Cinder Bed situation, where you’ve got a mixture of employees with different benefits and what kind of problems that has caused, we can see that same kind of friction happening on the Silver Line.”

In hopes of applying more pressure to Metro, Supervisor Jeff C. McKay — the county board’s newly elected chairman — said he planned to ask the Northern Virginia Transportation Commission to pass a resolution that seeks to get Metro to reconsider its plans for privatization on the Silver Line.

“The privatization that is happening at Metro is causing [the transit union], for good reason, to strike at Cinder Bed,” said McKay, who is among several county supervisors who sit on the board of the regional transportation commission.

“They’re concerned about the privatization of the Silver Line and they’re using the Connector negotiations as a way to fight that,” McKay said. ” I agree with that. People doing the same work should be getting the same wages.”

With the Cinder Bed Road labor talks making little progress, a Connector strike was not unexpected. A collective bargaining agreement between Connector operators and mechanics and Transdev expired Nov. 30, and workers had also authorized a strike two years ago after labor negotiations broke down with a different contractor at the time.

But in the Connector’s 30 years, strikes have been avoided in all but two or three occasions. In those cases, a stoppage didn’t last long, according to Fairfax County transportation officials.

Kate McSweeny, a vice president and general counsel for ACCSES, a service provider for people with disabilities, has ridden the No. 699 Connector bus from the Fairfax County Government Center to 18th and G streets NW in the District for two years. When she boarded the bus Wednesday night, she said, she hugged the driver, whom she recognized from past trips. They talked about the labor dispute, and the Connector operator said she doubted that a strike would happen. If it did, she told McSweeny, it would only last a short time.

McSweeny woke up Thursday to no ride.

“I ended up having to telecommute, which isn’t my choice for the day,” McSweeny said. “I think there should be some calling out. I don’t think the county has prepared.”

“That’s our tax dollars,” she said of the Connector’s service. “And at the end of the day, they negotiated this deal, and they need to fix it.”

Fairfax County Department of Transportation spokeswoman Anna K. Nissinen said the county is “encouraging these negotiations in good faith and hope that both parties are working diligently to restore service to Fairfax Connector passengers.”

Negotiators bargained for 10 hours Wednesday before the Connector strike was called, Transdev officials said. Union representatives wanted annual raises above 7 percent while Transdev was pushing for raises just above 2 percent.

Both sides returned to negotiations Thursday, and Mitun Seguin, spokeswoman for Transdev, said the difference between offers narrowed.

John P. King Jr., regional vice president of Transdev, said the union’s demands for raises comes after many Connector operators received as much as a 10 percent pay raise when Transdev took over operations of the service from another private company on July 1. According to Transdev, 410 of the 601 unionized Fairfax Connector employees make more than $32 an hour.

“We recognize that we are being paid by tax dollars,” King said. “The current proposals are not fair, balanced or reasonable, and that’s why the parties have to negotiate to get to a fair and balanced collective bargaining agreement.”