The number of longshore workers called to work overnight at the Ports of Los Angeles and Long Beach may be cut by two-thirds, the latest twist in the months-long contract negotiations between dockworkers and shipping lines at West Coast ports.

Adán Ortega, spokesman for the International Longshore and Warehouse Union Local 13 of Wilmington said that on Dec. 31, the union received notice from the Pacific Maritime Association, which represents shipping companies and other port terminal operators, that the number of nighttime work positions would be cut by two-thirds as of Jan. 2.

Ortega said that the positions affected would include include crane operators, drivers, signalmen and dock workers, and would last for an undetermined period of time.

Ortega said association sets a hiring schedule several days in advance and individual operators can either follow that schedule or do what they must to suit their individual needs, although they usually follow what the association advises. If terminal and shipping operators follow the association recommendations, it could take significantly longer for ships to be unloaded.

Steve Getzug, spokesman for the association, said the group notified the ILWU of the reductions to relieve potential gridlock at the ports. He said association is recommending a reduction in the number of workers that unload ships so that other dockworkers and truck drivers can focus on moving cargo that’s already been unloaded and has been stacked up at port terminals.

“To focus efforts on clearing containers from terminal yards and get them moving to their final destinations (small business, warehouses, distribution centers, retailers, etc.), PMA will be reducing the number of workers ordered to unload ships on night shifts, thereby avoiding the prospect of creating gridlock that the additional unloading of ships would create,” Getzug wrote in an email to the Business Journal.

Work orders for day shifts and night shift yard and gate workers – workers who don’t unload ships but work to move cargo in and out of the port – will not be affected, he said.

Ortega said the union and the association met Friday to discuss the situation. The ILWU said workers and local officials will meet late Friday afternoon at the union hiring hall in Wilmington to see whether individual terminal operators will comply with the association’s directive.