A Volkswagen employee prepares to install a back-up camera on a 2013 Passat at the Chattanooga plant.

The National Labor Relations Board has finalized a hearing for April 21 on the United Auto Workers request for a revote on unionizing Volkswagen's Chattanooga plant.

However, the location and time haven't yet been scheduled, according to the NLRB.

Earlier, the hearing was tentatively slated for April 7 in Chattanooga.

The federal agency said the hearing will be conducted on consecutive days until it is completed and will offer parties the chance to give testimony and to examine and cross-examine witnesses.

Within 14 days from the date of the issuance of the report, any of the parties may file exceptions with the Board in Washington, D.C. If no exceptions are filed, the NRLB may decide the matter upon the record or may make another disposition of the case, the Board said.

Last month, VW's hourly workers at the plant voted 712 to 626 against unionizing the factory after a two-year organizing effort by the UAW.

The UAW later appealed the outcome to the NLRB, saying that statements by third parties tainted the election, and it requested a revote at the plant.