A labor strike that would shut down six out of 10 of the busiest ports in the US just weeks before the presidential election is looking increasingly likely. 

Negotiations on a labor contract covering trade hubs from Boston to Houston have stalled since June when the dockworker union called off high-level wage talks with the United States Maritime Alliance, which represents ocean carriers and terminal operators.

The International Longshoreman’s Association now says it will present final contract demands to union delegates at a meeting on Sept. 4-5, and will also discuss strike strategies in the event a deal isn’t reached before the Sept. 30 deadline.

“With less than 30 days to go before the end of our current Master Contract when these meetings are held, we must prepare our locals and our ILA membership for a strike on Oct. 1,” said ILA President Harold Daggett in the statement on Saturday. The USMX declined to comment.

Global maritime trade is already under strain as container carriers avoid attacks by Houthis through the Red Sea and looming trade tariffs encourage importers to deliver goods before global trade wars heat up. 

Even the threat of a port walkout can be disruptive as shippers seek alternative routes for their imports and exports. West Coast ports lost market share during an extended round of contract negotiations between dockworkers and their employers that ended with a six-year deal announced last summer.

The ILA is demanding wage gains to make up for inflation and a share of the extraordinary profits won by ocean liners during the pandemic. The union is asking for more than the 32% increase won by West Coast counterparts last summer, and the two sides remain far apart on the scale of wage increases, according to person familiar with the talks.