CHICAGO (CBS) — At least 20 of the Chicago Public Schools’ more than 300,000 students are still reporting to their teacher right now, after the teacher crossed a picket line during the ongoing strike.

CBS 2’s Tara Molina sat down with Joseph Ocol, a CPS teacher who is speaking out against the strike that started Thursday. This is not the first time he has done so.

“I’m working for CPS. I’m working for the kids,” he said. “I’m not working for the union.”

We talked with Ocol after he refused to join a one-day walkout in 2016. Ocol was kicked out of the Chicago Teachers Union for refusing to join the union’s “day of action” in protest against the Chicago Public Schools administration and contract negotiations.

The CTU considered him a scab. But even after he was expelled from the union, Ocol said he would do it again.

“I’m just one teacher trying to do his job; trying to take responsibility to be the teacher, an effective teacher, for the students,” he said.

Ocol has been a teacher in the Chicago Public Schools for 15 years. He said he is standing up for what he believes in by not standing in line with the 25,000 members of the Chicago Teachers Union.

“I joined CPS as a teacher, not as a union member,” he said.

The math teacher and chess coach is the only teacher at Charles W. Earle STEM Academy, at 2040 W. 62nd St. in the West Englewood community, who has not gone out on strike.

“I am doing the right thing,” Ocol said.

He said he did the right thing when he crossed the picket line in 2016 too.

“We’re losing instructional time. Kids are losing. I don’t know if we will be able to recover this – the lost time and the lost opportunities of learning,” Ocol said.

His chess team went on to win the national championship in 2016. They took fourth place this year.

But Ocol said a strike that continues any longer will hurt them, and his students, in the long run.

“This is not about money. This is not also about politics. This is about the kids. This is about the children; their future. This is about the parents,” he said. “We are inconveniencing the parents.”

That is why Ocol has been showing up to school anyway, despite backlash that he’s all too familiar with.

When he was suspended from the union for crossing the picket line in the 2016 one-day walkout, he refused to fork over the one day’s pay from the strike. He said after that, the CTU continued to take dues from his paycheck until he filed a complaint in court.

As to teachers and CTU members who do not approve, Ocol said: “They won’t be happy, and well, I can only ask them as to why they want teachers to leave the students? I just cannot see the correlation. I cannot see the relevance. I cannot see – why do we have to sacrifice the kids?”

A CPS source said to date, 95 CTU members have crossed the picket line.

We reached out to CPS and the CTU for a response to Ocol’s decision. This story will be updated when we hear back.

Tara Molina