Around 1,000 challenged ballots have delayed a tally to determine whether or not eligible Harvard students voted to unionize, according to Boston's National Labor Relations Board general attorney Gene M. Switzer.

NLRB deputy regional attorney Robert P. Redbord said University officials and union organizers continued to work through the challenges on Tuesday. Votes are challenged at the time of the election and set aside if there are questions about voter eligibility, whether or not the voter submitted his or her ballot at an unassigned location, or whether the ballot matches the name on the list of eligible voters for a given location.

“The actual count will not be starting today,” Redbord said at lunchtime Tuesday.

According to Graduate School of Arts and Sciences spokesperson Ann Hall, about 3,500 graduate and undergraduate students were eligible to vote in last week’s historic, NLRB-supervised election, which will decide whether the Harvard Graduate Students Union-United Auto Workers—as of now, a union effort comprised of students across the University—will become a recognized union representing teaching and research assistants.

In an email sent Nov. 23 to eligible voters, Director of Harvard’s Office of Labor and Employee Relations Paul R. Curran wrote, “Because this is the first such election, the number of challenge ballots is not surprising.”

In his email, Curran wrote that the process would resume Nov. 29 after the break.

“The University respects the votes cast by students in this consequential election and, along with many others across our community, we are committed to ensuring that the ballots of all eligible voters are counted,” Curran wrote.

An HGSU-UAW Facebook post reads, “We will return to the NLRB next Tuesday to continue addressing the remaining challenged ballots and to continue to ensure a fair process,” and writing that while “a number of board challenges to voters not on Harvard's eligibility list” were resolved, “there are still hundreds remaining.”

—Staff writer Leah S. Yared can be reached at leah.yared@thecrimson.com. Follow her on Twitter @Leah_Yared.