Union members picket outside Bath Iron Works, Monday, June 22, 2020, in Bath, Maine. The union is warning outsiders not to cross its picket lines. Credit: Robert F. Bukaty / AP

Bath Iron Works’ largest union is warning outsiders to not cross its picket lines or be otherwise influenced by “propaganda” that it accuses the boatmaker of issuing to undermine the union or the strike as it enters its 18th day.

The International Association of Machinists and Aerospace Workers Local S6, which has about 4,400 of the total 6,600 workers at the Navy shipyard, issued a blunt message online Thursday that warned that it will fine members who cross picket lines.

“BIW has mailed out propaganda, had supervisors try to sell this contract based on economics, avoided the real issues, and irresponsibly provided information on how to resign from the Union so you can cross the picket line and work as a scab,” according to the statement. “Once we return to work, anyone who took the advice from management and resigned from the Union will still be required to pay full union dues. The Union will fine every single member who crossed the picket line for the total amount of wages they individually earned from BIW until the strike is over. BIW has once again steered you wrong.”

“No man has a right to scab so long as there is a pool of water to drown his carcass in, or a rope long enough to hang his body with,” the message concluded.

The shipyard said Friday that employees have a right to continue working under the law, with “the right to do so without being unlawfully harassed and threatened.” The statement also said workers who resign from the union to cross picket lines cannot be fined. About a dozen workers are thought to have crossed the picket lines, according to the Seattle Post-Intelligencer.

The strike is in its third week and is the first at Bath Iron in more than 20 years. About 87 percent of the union’s voting members opted to reject a three-year contract with BIW, citing subcontracting, health benefits and overtime, among other issues, on June 21. The strike began the next day. A federal mediator was due to start work this week to end the lingering stalemate.

Everyone from local leaders to former Vice President and likely Democratic presidential candidate Joe Biden has weighed in on the strike, generally asking both sides to get back to the table as soon as possible to mitigate the impact of the strike on the state’s economy, particularly amid the global pandemic. The company had begun making machines that make specialized swabs used for tests for the new coronavirus.

Bath Iron Works President Dirk Lesko said Tuesday that the strike was forcing the “temporary layoffs” of the company’s surveyors and trades inspectors ― some 25 to 30 workers could be laid off, according to one union representative.