The Chicago Teachers Union and ChiACTS — the union representing teachers at the city’s charter schools — moved one step closer to unifying Friday.

The union representing Chicago charter school teachers voted overwhelmingly — 671 to 130 — to join the Chicago Teachers Union. The CTU plans to take its own vote on bringing in ChiACTS in the fall.

“This vote for unification is a vote for educators with both ChiACTS and the CTU to speak with a stronger collaborative voice for real educational justice for all of our students,” Chris Baehrend, President of ChiACTS Local 4343, said in a statement issued Friday night.

Should the two unions come together, contracts for CPS-employed teachers and those hired by publicly funded, privately managed charters still would be separate, the Chicago Sun-Times reported last month.

“The CTU supports union rights for all educators in Chicago, including charter school teachers,” CTU vice president Jesse Sharkey said in the statement. “Local 4343’s vote for unity takes a stand for using our collective power to support quality public education for the students we all serve.”

Members of ChiACTS — the largest charter school union in the country — recently threatened strikes against three of Chicago’s charter school operators — the UNO Charter School Network, ASPIRA charter schools and Passages Charter School.

None of the threatened strikes — which would have been the first in the nation of charter teachers — happened. Most recently, the Passages contract dispute was settled late last week, shortly before a strike deadline.

The membership of the Chicago Teachers Union has been dwindling as Chicago Public Schools officials have closed schools and cut staff at its schools while expanding its charter portfolio.

The CTU once considered charter schools the enemy, and it bargained hard in its most recent contract for a cap it won on charter schools expansion. But the union since has embraced ChiACTS as that union has organized staffers in 32 of about 130 charter schools in Chicago. Both unions use the same attorney for contract negotiations, and CTU organizers frequent ChiACTS picketing events, too.

Contributing: Lauren FitzPatrick