Workers at Ikea's first factory in the United States have voted to be represented by a union, the latest development in a bitter campaign that has challenged the low-cost home furnishing company's reputation as a worker-friendly employer.

Employees at the plant in Danville, Va., voted 221-69 on Wednesday to allow the International Assn. of Machinists and Aerospace Workers to negotiate salary and benefits with the retailer's manufacturing subsidiary, Swedwood, a spokeswoman for the union said. The National Labor Relations Board confirmed the results.

The next step will be for the union to represent workers in collective bargaining, something that could be a protracted process. An Ikea spokeswoman did not respond to requests for comment.

In the weeks leading to the vote, the factory hired the law firm Jackson Lewis, which has made its reputation keeping unions out of companies. Workers said Swedwood officials required employees to attend meetings at which management discouraged union membership.