The start of in-person classes for some special-education students and preschoolers in Seattle has been rescheduled for March 29 instead of this Thursday, according to a Tuesday release from Seattle Public Schools and the union representing its educators.

The announcement comes after intense opposition from the union to the district’s move to summon 700 educators back to buildings this week to teach students ahead of an agreement on expanding in-person instruction. Those educators were supposed to report to their buildings on Monday to ready their classrooms for learning, but a campaign by the union — the Seattle Education Association — asked them to stay remote.

“SPS and SEA together agreed that school staff could benefit from additional time to prepare to offer the safest, most equitable in-person learning environments possible in every SPS building,” the release said.

A safety check of some district buildings by union and district officials, an independent HVAC system contractor and the state Labor & Industries department found no major issues, according to the release.

The two parties are still working on an agreement to offer in-person services to around 10,000 students, including kindergartners and first-graders. The timeline is the first jointly released by management and labor for any type of in-person instruction since the pandemic began.

It’s unclear when negotiations will conclude.