The Denver teachers union will have an acting president for more than three months this summer until it can redo an incredibly close election in which no candidate was declared the winner.

Union officials confirmed to Chalkbeat on Monday that they will hold a new election this fall. On Tuesday, six weeks after the original election, the union sent an email update to its members. The email says that until the new election is held in September, newly elected vice president Rob Gould will serve as acting president of the Denver Classroom Teachers Association.

Gould’s position as chief union negotiator during contentious teacher pay negotiations and a three-day strike earlier this year made him popular among educators. He ran unopposed in April for the position of vice president.

The summer is a critical time for union leadership. A Denver school board election in November presents an opportunity for union-backed candidates to win a majority on the board for the first time in years. In the last election in 2017, the Denver Classroom Teachers Association made its endorsements in early August. The endorsements matter because the union’s donor fund has historically spent hundreds of thousands of dollars to get its candidates elected.

Two teachers ran in April for the position of union president. When ballots were first counted, only 11 votes separated them — a close election that signaled division in the ranks of a union that earlier this year won a significant raise by going on strike.

Henry Roman, the longtime union president who was going for a sixth two-year term, won 1,073 votes. Challenger Tiffany Choi, a French teacher who wants to see the union focus less on internal business and more on social justice, won 1,062 votes.

The 11-vote difference — about half a percentage point of the votes cast — was within the threshold for an automatic recount under the union’s rules. But after the union threw out ballots from several schools because of suspected irregularities, some teachers called for going beyond a recount and holding the election over again.

Unlike the electronic voting system the union used to poll members about whether to strike, it has used paper ballots for its officer elections. The voting is overseen by union representatives at each school, and the ballots are counted centrally.

A teacher who said she attended the April vote counting explained on Facebook that a school’s ballots are thrown out if counters suspect that non-union members voted, or if the number of ballots does not match the number of signatures on a sign-in sheet.

The email the union sent to its members Tuesday emphasized the importance of following the voting rules in September’s election to avoid invalidated ballots. Union members will vote for president, as well as for a seat on the board of directors that was also too close to call.

“Every single vote will matter and make a difference since it is quite likely that the final count spread between our candidates again will be expressed in single or double digits,” it said.

Union elections are internal matters that are not overseen by any state agency, said Dean Conder, the labor relations administrator at the Colorado Department of Labor and Employment. That means the conduct of elections is governed entirely by union bylaws. School districts don’t have to recognize or bargain with unions, either — though many, including Denver Public Schools, do.

In February, the Denver teachers union went on strike after more than a year of negotiating with the district over a new teacher pay system. After three days, the union and the district signed an agreement that will give teachers an average raise of nearly 12 percent next year.