The International Longshoremen’s Association union has threatened to strike if it does not reach a new labor agreement by Sept. 30. The union represents 45,000 workers at 36 ports, including New York, New Jersey, Houston, and Savannah. 

Nearly half of U.S. ports would be affected by the strike. Retailers, manufacturers, and other ocean shippers have already begun moving some of their cargo through the West Coast as a precautionary measure to avoid the chance their cargo is stuck in the affected ports, according to Reuters. 

“We are very far apart,” Harold Daggett, the union president, said earlier this month. “Mark my words, we’ll shut them down Oct. 1 if we don’t get the kind of wages we deserve.”

Consumers likely would not notice any major shortages of retail goods if the strike were to be resolved within a few weeks. However, if the strike lasted more than a month, it would cause a shortage of some goods, according to CBS News. A prolonged strike would affect the overall economy. 

“I think everyone’s a bit nervous about it,” said Mia Ginter, director of North America ocean shipping for C.H. Robinson, a logistics firm. “The rhetoric this time with the ILA is at a level we haven’t seen before.”

Transportation experts believe that goods coming to North America from Europe and West Asian countries rely on direct routes across the Atlantic Ocean and would be most heavily affected. Analysts at Sea-Intelligence, a Copenhagen-based shipping advisory firm, estimated it could take four to six days to clear the backlog from a one-day strike.

“The moment you close the door, things begin to back up,” George Goldman, CMA CGM’s North America chief, said on a webcast hosted by the Port of Los Angeles. “One day is too long for port closures.”

President Joe Biden’s administration said it would not move to block the strike. 

“We’ve never invoked Taft-Hartley to break a strike and are not considering doing so now,” the Biden administration official said. “We encourage all parties to remain at the bargaining table and negotiate in good faith.”

The Taft-Hartley Act, enacted in 1947, subjected unions to the National Labor Relations Board’s unfair labor prices, restricting the power of labor unions.

Meanwhile, ports on the West Coast have already seen a surge in activity due to the looming strike. 

In August, the Port of Long Beach in California saw its busiest month in its century-long history. There, volume increased nearly 34% from the year before because of a 40% surge in imports. The Port of Los Angeles also saw an increase in the volume of imports in August, jumping 16% because of a nearly 18% increase in imports.