As the deadline looms for a new labour contract to be agreed covering dockworkers at 30 West Coast ports, industry officials are warning of "significant" disruption to the US economy if a shutdown occurs.

The current contract for the 13,600 dockworkers expires on Monday (30 June), and the worry is that if talks break down, a protracted dispute could lead to reduced or shuttered terminal operations.

While it is possible that talks may extend past this date without a strike being called, industry groups fear a port closure would mean a delay in back-to-school and holiday shipments.

A new study, conducted for the National Association of Manufacturers (NAM) and the National Retail Federation (NRF) by economists at the Interindustry Forecasting Project at the University of Maryland, found the economic repercussions of a port closure would grow with time.

Under a 5-day stoppage the US economy could lose $1.9bn a day, while this would rise to $2.1bn and as much as $2.5bn a day if the stoppage runs to ten and 20 days respectively.

"Any supply chain disruption, whether it's a port slowdown or outright stoppage, would cripple international trade, stymie supply chains and hurt domestic employment and consumer spending," warns NRF president and CEO Matthew Shay.

"For retailers and their customers, a port closure would mean a delay in back-to-school and holiday shipments that could significantly drive up consumer prices."

The last major West Coast port disruption occurred in 2002, when management locked out dockworkers for ten days.

Separately, US Customs and Border Protection (CBP) has released general vessel, cargo and entry guidelines in preparation for the "major delays and diversions" at West Coast ports.

Click on the following link to read the document: Interim procedures for vessel and cargo entry processing for possible West Coast trade disruptions.