(Bloomberg) -- Chicago public school teachers are moving toward a strike in the nation’s third-largest district as union members voted to only work remotely, prompting officials to delay teachers’ required return to classrooms this week by two days.The Chicago Teachers Union said in a statement Sunday that 71% of its voting members approved a resolution to “conduct remote work only” when kindergarten through eighth-grade teachers were scheduled to report to work in-person on Monday, according to the union, which cited safety concerns.After the union released the vote results, the district pushed back teachers’ required return to Wednesday to create more time to reach an agreement, school officials said. Kindergarten through eighth-grade students have the option to return Feb. 1.“We now agree on far more than we disagree, but our discussions remain ongoing, and additional time is needed to reach a resolution,” Chicago Public Schools Chief Executive Officer Janice Jackson and Chief Education Officer LaTanya McDade said in a statement.School officials want to avoid the second strike in as many years for the district. The clash over reopening comes as school administrators across the country are grappling with how to bring students back to the classroom amid the pandemic and slow ramp-up of vaccinations.U.S. President Joe Biden has vowed to reopen most schools in his first 100 days and has directed the departments of Education and Health and Human Services to provide guidance on reopening.Biden’s Bid to Reopen Schools Risks Reigniting Union TensionBargaining Continues“We will continue to work remote so we can keep ourselves, our families and our school communities safe,” the teachers’ union said in its statement, noting that bargaining continues. “If we are locked out by the mayor and CPS, then the choice to strike is theirs, not ours.”Chicago Public Schools plan to offer in-person instruction amid a broader easing of Covid-19 restrictions in the city and across Illinois, where average positivity rates and case numbers have been falling. In Chicago, the seven-day rolling positivity rate is 7.3%, down from 9.1% a week earlier, according to the latest data on the city’s website.On Friday, Jackson said that it would be considered a strike if teachers don’t report for work. The district is confident it can reopen buildings safely for more than 70,000 kindergarten through eighth-grade students on Feb. 1, according to Jackson. In-person learning began almost two weeks ago for the first time since March for preschool and special-needs students. Not all teachers have reported in-person as required, and not all students who had indicated they would return to buildings have done so.Jackson said the past two weeks have shown that safety protocols are working. The district plans to start offering vaccinations to employees in mid-February.The union said 86% of its members participated in the vote, which took place Thursday through Saturday.‘Too Risky’Kirstin Roberts, a preschool teacher at Brentano Elementary, said she wants more specific plans that do more to improve safety and prevent the spread of Covid-19 in school buildings.Roberts, who voted to stay remote and declined to return to in-person instruction earlier this month, wants detailed protocols for testing, contact tracing and vaccinations, as well as improvements in remote learning for those students who don’t choose in-person instruction.“CPS has a lot of work to do,” Roberts said. “The virus is not under control.”(Updates with district quote in fourth, teacher comments starting in 12th paragraph)For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.