Can a party challenge the eligibility of a person to vote?

Yes.  A party or the Regional Director, for good cause, may challenge the eligibility of any person to participate in the election prior to the employee voting.  In this instance, the individual who is the subject of the challenge is given the opportunity to vote a challenged ballot.  Any ballots that remain unresolved after all ballots are counted and a tally of ballots is issued are impounded and preserved, in case it is necessary for the Regional Director to determine if the voter was eligible to vote in the election.