Students affected by the ongoing teachers' strike at public elementary and high schools across Ontario will not be given standardized tests due to the ongoing job action.

In a memo sent on Thursday to the directors of education at the elementary and secondary school levels, the EQAO's chief assessment officer said testing materials will not be delivered to "any schools that are experiencing labour action."

This includes all elementary schools in the public system and high schools in Peel, Durham and Sudbury, where teachers have walked off the job.

"We are disappointed that labour disruptions may impede the administration of the provincial assessments in English-language public schools and about the resulting loss of important information that students, parents and all other education stakeholders rely on," Debra Rantz said.

The memo didn't say when the EQAO testing materials will eventually be sent to schools. A spokesperson for the Toronto District School Board said in a tweet Thursday afternoon that standardized tests for students in Grades 3 and 6 will be "postponed until further notice" due to the ongoing, province-wide work-to-rule campaign.

"We have been notified by EQAO that Grade 3 & 6 assessments have been postponed until further notice due to ongoing labour actions," the spokesperson said.

On Monday, teachers in public elementary schools began the first phase of a province-wide strike. Although extracurricular activities and field trips will continue, there will be no standardized tests and teachers will not perform some of their administrative duties. That includes writing comments in report cards, and participating in meetings and professional development related initiatives.

The union representing the province's teachers, occasional teachers and education professionals in public elementary schools told its members about the work-to-rule action in a memo earlier this month.

The president of the Elementary Teachers' Federation of Ontario hasn't said what a second phase of the strike could entail.

"This strike action is incremental in nature," Sam Hammond said last week. "It will continue in its current form until the (the government and school boards') demands are withdrawn from the bargaining table or ETFO deems that further actions are required."

The ETFO has previously said they were "forced" to strike because of demands tabled by the Ontario Liberal government and the Ontario Public School Board Association. Those demands include the school board's ability to increase class sizes, and authority to direct how teachers should spend their prep time.

This is the first time the OPSBA has participated in the central negotiations.

The elementary strike comes as more than 70,000 high school students in the province are not in class because teachers in the Peel, Durham and Sudbury have walked off the job.