The letter, delivered Tuesday on the final day of City Council budget hearings, lays out six major objections to the mayor's plan, which relies on a revived corporate head tax and a series of other revenue measures the opposition bloc has already rejected.

"You were told that a tax on jobs, which hinders our city's ability to grow, would not get our votes. Yet, you put it in your budget anyway," the aldermen wrote, referring to Johnson's proposed $25-per-month, per-employee tax on businesses with more than 125 employees. "Taxing jobs prevents growth and moves the city in the wrong direction."

The letter warns that employers weighing expansion can choose the suburbs or another state, and that "every job that goes elsewhere takes with it the paychecks, spending and property taxes that makes up the city's tax base."

The opposition also flagged Johnson's proposal to raise the city's tax on equipment rentals and cloud computing from 15% to 20%—already the highest such levy in the nation. The aldermen noted that last year's management ordinance tied to the 2026 budget included a two-year freeze on that tax, and they accused the mayor of breaking that commitment.

"Moving the rate from 15% to 20% is a tax increase on every Chicago business and individual who leases equipment or pays for cloud software—from the neighborhood restaurant renting its dishwashing machine and point-of-sale system to the family renting equipment from the hardware store to clean out a flooded basement," the letter states. "We will not break our word on the cap we imposed last year."

Acting Budget Director Jonathan Ernst has defended removing the freeze, arguing the economy is shifting toward cloud-based services and away from traditional tax bases. "This is where the economy is moving toward, away from areas that we typically tax," he said. "We need to evolve with that."

The aldermen further charge that nearly half of the budget gap was closed with one-time money and borrowing that will not be available next year. They cite a $75 million up-front payment from the New York investment firm that acquired Chicago's parking meters, $37.7 million from the moribund Catalyst Fund, and $480 million in borrowing to pay settlements tied to police wrongdoing.

Johnson is also accused of leaving "billions of dollars owed to the city sitting on the books" and of adding tens of millions in new spending while claiming $119.8 million in savings without itemizing any of it.

"Aside from cutting police positions, your proposal appears to mostly shift recurring costs onto other city funds. That is cost shifting—not making government more efficient," the letter states. "Growing spending in the middle of a $882 million budget gap is unfathomable, and every new dollar becomes a recurring cost with no plan to pay for it in future budgets."

Johnson pushed back Tuesday, saying his critics have offered no alternative.

"No one has come up with a viable solution other than saying what they do not want," the mayor said. "People have to come to the table saying what they do want. What are they willing to do?"

He argued that if aldermen support his investments in mental health, sanitation, libraries, and youth jobs, they must find a way to fund them. He also tied the national Democratic wave to a rejection of austerity, saying the midterm victories were "not about cuts, consolidations, efficiencies and neo-liberal politics and austere budgets," but about "making sure that we are improving the quality of life for everyday people."

The standoff echoes last year's budget fight, when a 31-member coalition seized control of the process and passed an alternative revenue package after rejecting Johnson's corporate head tax. This year, with mayoral and aldermanic elections three months away, the opposition bloc is signaling it will not do the heavy lifting again.

"We are telling you now with 51 days left before the City is required to have an approved budget so your team has ample time to write a budget that can earn the votes of this Council instead of spending the next several weeks defending one that cannot," the letter concludes.

The budget must be approved by the end of the year. Without a council majority, Johnson faces the prospect of a government shutdown or a rushed compromise in the coming weeks.