DUBLIN, VA—Workers at Volvo’s truck assembly plant here are walking a picket line again after a 37-day negotiating truce ended with a “no” vote on the company’s latest contract offer.

Workers ended a 13-day strike April 30 after Volvo Trucks North America brokered a peace agreement with the UAW: Talks would begin again and so would the work.

The talks, which had begun in February, did resume while the plant’s 2,900 UAW members worked under the terms of an expired, five-year contract that had been reached in 2016. Since then, UAW workers voted “no” on a May 16 contract proposal and “no” again on a revised offer June 6. It was after the latest decision that workers resumed their strike June 7.

According to a report, 91 percent of union members voted against the salary language and 90 percent voted “against hourly and common language in the proposed six-year agreement.” This amounts to an even steeper defeat than that which applied to the contract that was voted down in May.

Franky Marchand, the plant’s vice president and general manager, called the action “difficult to understand,” and said the union leadership had previously endorsed the tentative agreement prior to the vote. He added that the plant was still committed to the collective bargaining process and remained confident an agreement would eventually be reached. Union leaders suggested the same, and said they’d be available to resume talks again this week.

In the meantime, the plant—which employs 3,300 workers and is the largest Volvo truck factory in the world—will move forward without 2,900 union members. In the midst of this conflict, Volvo is investing $400 million to upgrade the plant and plans to hire 600 more workers before year’s end.