With dockworkers on the East and Gulf coasts threatening to strike Oct. 1, businesses have been accelerating imports, redirecting cargo and pleading with the Biden administration.

Some importers started ordering Christmas goods four months earlier than usual to get them through the ports before a labor contract between the operators of port terminals and the International Longshoremen’s Association expires Monday.

Many shipments have been diverted to West Coast ports, where dockworkers belong to a different union.

Despite those measures, even a short strike could lead to significant disruptions. JPMorgan transportation analysts estimate that a strike could cost the economy $5 billion a day, or about 6% of gross domestic product. For each day the ports are shut down, the analysts said, it would take roughly six days to clear the backlog.

Last week, scores of trade groups sent a letter to the Biden administration, imploring it to help forge a deal between the ILA and the United States Maritime Alliance, a group of companies that move cargo at ports.

On Friday, top Biden administration officials met with port operators.

They told members of the Maritime Alliance that they should be at the table with the union and negotiating ahead of the contract expiring. That’s according to a White House official who insisted on anonymity to discuss the private meeting.

Administration officials have delivered a similar message to the union this week.

In its own statement Monday, the union disputed the idea that it was refusing to negotiate and said the alliance was offering wage increases that were unacceptably low.

Administration officials have said President Joe Biden is not planning to force dockworkers back to work, which the 1947 Taft-Hartley Act authorizes him to do.

A strike would close huge container ports in New Jersey, Virginia, Georgia, Texas and Maryland.

The ILA, which has more than 47,000 members, and the Maritime Alliance have not met in person since June, when the union broke off talks over what it claimed was unauthorized use of labor-saving technology. And it wants to increase wages, which have been significantly eroded by the high inflation of the past few years.

The union and alliance both declined to comment or answer emailed questions.

This report contains information from the Associated Press.