CHICAGO — An explosive revelation is rocking an already competitive mayoral race here after incumbent Lori Lightfoot’s campaign emailed Chicago public school teachers, in a system she oversees, asking them to recruit students. to volunteer in his campaign for school credits.

Now, the Chicago Public Schools inspector general is investigating the matter, critics they are calling for more extensive investigations, and their opponents are piling up.

All of this threatens to further complicate Lightfoot’s already bleak road to re-election in February, in which he has lagging behind in the polls.

The Chicago Public Schools Office of Inspector General confirmed to NBC News on Thursday that it had «opened an investigation into this matter and we are currently gathering information to determine what, if any, policies have been violated.»

The investigation comes after a deputy campaign manager emailed public school teachers — via government email — asking them to recruit students to volunteer for Lightfoot’s campaign in an “internship program,” where students could earn academic credit. Chicago PBS station, WTTW News, first reported the emails.

“We are simply looking for enthusiastic, curious and hard-working young people eager to help Mayor Lightfoot win this spring,” the aide said in the email obtained by WTTW News.

The email comes just as a nine-way mayoral battle is underway and Lightfoot is facing formidable opponents, including Chicago Rep. Jesus «Chuy» Garcia and Paul Vallas, former superintendent of Chicago schools.

“It could suggest that a sense of desperation is setting in,” Vallas said of the school’s recruiting effort.

Vallas called for a thorough investigation into the extent of the campaign’s involvement, including whether anyone shared government email lists with a political entity.

“I can’t believe CPS did this without some kind of clear message from City Hall,” he said.

Another mayoral candidate, Chicago Councilwoman Sophia King, said the email itself was the kind of thing that «gives Chicago a bad name.»

«I really think this is egregious, and if she had anything to do with it, she should resign,» King said of Lightfoot.

As mayor, Lightfoot directly oversees Chicago schools and appoints the superintendent and members of the board of education.

After news of the email broke Wednesday, the Lightfoot campaign issued several statements saying that campaign staff «have been reminded of the strong wall that must exist between the campaign and official activities and that contacts with any Chicago city or other sister agency employees, including CPS employees, even through publicly available sources is off limits.

When asked about the inspector general investigation Thursday, his campaign released a statement saying: “If there is an Ethics Board investigation, we will address it at that time. We are committed to running an ethical and transparent campaign, and we will continue to do so in the weeks and months ahead.»