Powell’s Books’ unionized workers have voted to authorize a strike, turning up the pressure on the prominent independent bookstore as contract negotiations continue.

On Wednesday, the International Longshore and Warehouse Union Local 5 announced that 92% of Powell’s workers voted in favor of the strike authorization. The union said it would decide whether to strike after its next bargaining sessions at the end of the month.

“This vote gives the ILWU Local 5 bargaining team the authority to call for a strike if it becomes necessary in the course of negotiations,” the union said in an Instagram post. “It doesn’t mean Powell’s workers are going on strike right away, but it does mean they have the option and are getting strike-ready!”

The local, which was founded by Powell’s workers in 2000, said that it isn’t asking supporters to boycott the bookstore amid ongoing negotiations. The union today represents other organizations including the Community Cycling Center, the Oregon Historical Society and the Interfaith Movement for Immigrant Justice.

Myka Dubay, a representative of ILWU Local 5, said negotiations with Powell’s Books have been ongoing since early February and that the landmark bookstore “has continued to be unwilling to provide a reasonable wage for workers.”

Dubay said both parties have previously “reached a number of ‘tentative agreements’ for a lot of different proposals” but that none of them have materialized into a set agreement. They said the two parties are in disagreement over wages and health care.

They said the bookstore is proposing a change to the workers’ current health care plan to one with fewer benefits, where employee’s will have to pay higher deductibles and out-of-pocket maximums.

Dubay said the union is pushing for a living wage and to make health care coverage more affordable for workers.