Occupy Oakland protesters stand atop a railroad scaffold at the Port of Oakland on Nov. 2 in Oakland after a day-long citywide strike. (By Noah Berger/Associated Press)

“We present this call to you because we believe it is time the occupation movement begins to work together to carry through coordinated, pinpointed actions. ... We will blockade all of the West Coast Ports on December 12th in solidarity with longshoremen, port workers and truckers in their struggle against the 1 percent!” the official West Coast Port Shutdown site read.

But port workers and operators say they are not in support of the shutdown, which is planned for ports in San Diego, L.A., Oakland, Portland, Vancouver, Tacoma and Seattle.

The Port of Oakland has already sent an open letter to the community to ask that the shutdown be prevented. In the full-page ad, which ran Sunday in the Oakland Tribune, the Board of Port Commissioners calls the shutdown a “bad idea.”

“Another shutdown will only make things worse – diverting cargo, tax revenue, and jobs to other communities,” the letter read. “It will hurt working people and harm our community.”

The International Longshore and Warehouse Union, which represents workers at the Port of Portland and has supported the Occupy movement in the past, says it will not support a “third-party strike like the one planned for Dec. 12.

Occupy Wall Street wrote on its Web site that protesters would have “full political and material support ... in whatever ways are necessary” to shut down the ports.