Inside Mayor Brandon Johnson's CPS-CTU tension

Mayor Brandon Johnson is reportedly moving to replace CPS chief executive Pedro Martinez at a crucial point in Chicago Teachers Union contract negotiations, sources told WBEZ and the Sun-Times this week.

Why it matters: Amid CTU complaints over Martinez's bargaining stances , a mayoral effort to remove him would upend longtime dynamics that placed the mayor with CPS leadership across the negotiating table from the union — Johnson's old employer.

Catch up quick: That dynamic started shifting last month when Martinez and the school board defied Johnson by releasing a CPS budget that did not include his requested allocations for $175 million in pensions and CTU contract costs.

• The mayor had suggested that CPS leaders take out a high interest loan to cover those expenses, but they resisted in the name of fiscal responsibility and were applauded by the Civic Federation for doing so.

The big picture: The potential shakeup is playing out at a delicate time for the mayor — days before he hosts the Democratic National Convention and less than two weeks before the start of the school year .

Reality check: Johnson cannot fire Martinez. Only the school board can, and it does not appear intent on ousting anyone at this point.

What they're saying: "The Chicago Board of Education, CEO Martinez, and Chicago Public Schools leadership are focused on preparing for a smooth start to the school year on Aug. 26," CPS and the board told Axios in a statement.

• "We're excited to work together with our school leaders, educators, and parents to continue to put the needs of our students first and build on our academic growth of the past two school years."
• The mayor's office told Axios that it does not comment on personnel matters.

The other side: "We need a CEO who is working on behalf of Chicago students and not the Civic Committee of the Commercial Club," the CTU told Axios on Thursday.

• "A CEO who's not just negotiating his contract but also a contract that delivers the schools that Chicago students deserve."

What's next: As Chalkbeat points out, if the current board doesn't act, the decision could be left up to a brand new 21-member school board that will start in January 2025.

• Voters will elect 10 members in November, and an additional 11 will be appointed by the mayor.