The president of the Chicago Teachers Union, who has been a vocal critic of Democratic Mayor Lori Lightfoot – at one point calling her "relentlessly stupid" -- says he won’t seek a fifth term, according to a report.

Jesse Sharkey’s decision was reported Wednesday by FOX 32 of Chicago. It comes amid several personal issues for Sharkey, the report said: His mother died in October 2020, his CTU predecessor and ally Karen Lewis died last February and his two sons are now in high school and college, the report said.

Sharkey will serve until June, FOX 32 reported.

"Our union will remain a force, and our dogged defense of public schools and the willingness to speak truth to power are not going anywhere," Sharkey said, according to the report. "But I am. Because it is time."

Sharkey, 52, said he intends to return to teaching.

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"I will not be leaving the movement, the labor struggle or this union," he said. "I will return to where my journey began: the classroom. I will do so with fondness for my time in leadership, because I had the joy and privilege of representing educators who care."

Public school students protest outside the Chicago Public Schools headquarters after walking out of their classrooms on Jan. 14, 2022, in Chicago. (Getty Images)

A Maine native, Sharkey didn’t rule out possibly running for mayor, the Chicago Sun-Times reported. The 25,000-member CTU is likely to back a candidate next year to run against Lightfoot if she seeks a second term, the report said.

Lightfoot's ‘talking point’

In January, Sharkey accused Lightfoot of opposing remote learning in schools only as a convenient political "talking point."

"I hear the mayor say that she doesn’t want to do remote," Sharkey said. "But honestly, that’s just a talking point, it’s an idea, ‘remote is bad.’ Remote education is a tool. Teachers view remote education, yeah, it’s not as good as in-person."

Just two days after those remarks, Sharkey slammed Lightfoot as "relentlessly stupid" as the city’s public school students were missing their fourth straight day of classes amid a dispute between Chicago Public Schools and the teachers union over coronavirus safety measures.

School administrators decided to cancel classes rather than allow remote learning as coronavirus cases rose in the city.

"We feel like we’re at a point where we don’t have enough at the table to be able to go back to the people who, frankly, have sacrificed a lot at this point, and confidently say, ‘This is something that can help us ensure our safety," Sharkey said Jan. 10. "The mayor is being relentless, but she’s being relentlessly stupid, she is being relentlessly stubborn."

"The mayor is being relentless, but she’s being relentlessly stupid, she is being relentlessly stubborn."

— Jesse Sharkey, CTU president

Chicago Teachers Union President Jesse Sharkey speaks in Chicago, Dec. 12, 2020.  (Getty Images)

He claimed Lightfoot was to blame for stalled negotiations.

‘We don’t like bullies'

"We don’t like bullies, we don’t like tyrants," Sharkey said. "We’re not going to be bullied or pushed into a corner. So that’s where we’re at right now."

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A day before those remarks, Lightfoot had blasted the CTU on national television, during an appearance on NBC’s "Meet the Press."

"If I had a dollar for every time some privileged, clouted White guy called me stupid, I'd be a bazillionaire."

— Lori Lightfoot, Chicago mayor

Mayor Lori Lightfoot presides over a City Council meeting on Oct. 27, 2021, in Chicago. (Getty Images)

"Fundamentally what we cannot do is abandon the science. We know that the safest place for kids to be is in-person learning in schools," Lightfoot told host Chuck Todd. "And we’ve spent hundreds of millions of dollars to make our schools safe. They are safe. We’ve got the data to demonstrate that. We’ve got to get the teacher’s union to get real and get serious about getting back into in-person learning."

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In another interview, Lightfoot, who is Black, hit back at Sharkey over his "relentlessly stupid" insult.

"If I had a dollar for every time some privileged, clouted White guy called me stupid, I'd be a bazillionaire," Lightfoot told Chicago’s WLS-TV.

The city and the union ultimately reached a deal late Jan. 10 that brought teachers and students back to classrooms.

Fox News’ Greg Norman contributed to this story.