NORTH CHARLESTON, S.C., May 31 (Reuters) - A small group of workers at Boeing Co's South Carolina jetliner factory is voting on Thursday on whether to form a "micro union," despite efforts by Boeing to challenge the election.
The National Labor Relations Board said last week that 178 Boeing flight-line readiness technicians and technician inspectors could lawfully take a vote on whether to join the International Association of Machinists and Aerospace Workers, and set the election for Thursday.
In a motion filed last week to the labor regulators, Boeing called the proposed bargaining unit "an artificially gerrymandered sub-set of employees." Boeing asked them either to stay the election or impound the ballots pending a decision on whether the small bargaining unit is lawful.
On Wednesday, the NLRB denied Boeing's request, according to a copy of the board's order sent to union organizers. Boeing did not immediately respond to a request for comment.
The go-ahead for the vote came five months after the labor board in another case made it easier for companies to challenge micro unions, reversing an Obama-era decision that had been sharply criticized by companies.
Forming smaller bargaining units can be a key organizing strategy for unions, particularly when they lack support from a majority of an employer's workforce. But business groups say that smaller bargaining units fracture workplaces.
This is the machinists' third attempt to organize Boeing workers at the company's only jetliner assembly plant outside Washington state. Boeing employs about 6,800 people at the North Charleston plant, which makes 787 Dreamliners and is the only site that assembles the largest version, the 787-10.
Boeing workers voted 2,097-731 last year to reject the union, Boeing said in documents filed with the NRLB. In 2015, the union withdrew a vote petition, citing "a toxic environment and gross violations of workers' lawful organizing rights."
South Carolina is a "right-to-work" state, one of 28 states that bar unions from requiring workers to join up as a condition of employment.
Some workers at the factory want the union to help with pay, the lack of opportunity to become managers, sudden schedule changes and mandatory weekend overtime work.
"There's a large contingent on the flight line that asked IAM to come back this year and organize us," Curtis Williams, 52, a flight-line readiness technician, said on Wednesday.
Workers received a raise last year, but flight-line technicians at the plant earn about 30 percent less than their counterparts in Washington state, Williams said.
The machinists' union represents about 30,000 workers at Boeing's factories in Washington state and has 600,000 members, including active retirees.
(Reporting by Harriet McLeod; Editing by Alwyn Scott and Peter Cooney)