CHARLESTON, S.C. — The National Labor Relations Board is considering whether some employees at Boeing’s plant in South Carolina can vote to join the International Association of Machinists union.

Local media outlets reported attorneys for Boeing and the union opened their case Tuesday in Charleston.

At issue is whether 178 flight readiness technicians and inspectors at Boeing’s plant in North Charleston can vote on whether to join the union.

Boeing says that group is too hard to set different rules for and any union vote should include all 3,000 production employees. The larger group rejected unionization by a three to one margin last year.

No decision is expected for several weeks.

The union says the smaller group has different duties and should be allowed to vote separately.