Chicago Public Schools leaders told families Thursday that classes will begin on schedule, but they gave few details about how the district might reverse layoffs after the board approved a budget that counts on $150 million in new state funding.

CPS CEO Macquline King said last week she was unsure whether schools would start as planned. She warned the school board’s revised $10.11 billion budget could make lenders less willing to provide short-term loans needed to cover payroll.

But during a community webinar Thursday, King said officials “feel really comfortable and confident that school will open on time, with no interruptions.”

The $150 million budget amendment, passed by board members aligned with the Chicago Teachers Union, calls on the district to reverse the layoffs of 760 teachers and 800 school-based support staff announced last month. That money also would cover a proposed midyear spending freeze, though it depends on the district securing the unconfirmed state aid.

Principals, however, will not need to re-open their school budgets, a CPS spokesperson said. It’s still unclear how or whether the district will add back laid-off positions.

CTU sent a letter to district leaders Monday, obtained by the Tribune, asking for impact bargaining to “ensure the prompt rescission of layoff notices” issued to its members.

The union and its allies argue the revised budget is a pressure tactic to force Springfield to confront decades of underfunding of CPS. They also point to recent commitments from several lawmakers to lobby for more money, including Illinois House Speaker Emanuel “Chris” Welch.” The union also notes the district is only considered 73% fully funded under the state’s own funding formula.

The union criticized the district for saying the school calendar might be affected by the revised budget, telling members last week that CPS “sent an email to parents to warn that the sky is falling” and “representing bankers’ interests over the interests of our school communities.”

But district leaders countered that the budget is not balanced under state law, and argued it could lead to midyear cuts if the money doesn’t come through. Because lenders and credit rating agencies are skeptical of unconfirmed revenue, the move could lead to credit downgrades and higher borrowing costs, officials said.

Getting additional funding from the state will be a steep hill to climb. Any supplemental funding bill would require a three-fifths supermajority in Springfield, and the money may not reach the district in time to affect this fiscal year.

Emila Zoko, the district’s acting chief budget officer, said at the webinar that the district will be leading a campaign to lobby Springfield and “will be keeping an extremely close eye on the situation.”

“Securing additional funding will be CPS’ immediate priority in our discussions with lawmakers,” Zoko said.

Welch, who pledged to CTU members that he would fight for more money during an Illinois Federation of Teachers meeting last week, has yet to offer details on how he aims to secure additional funding — or where the money might come from.

“The number $150 million never came up with me. I was talking in general, that I’m gonna go to Springfield and do what I do and lead that fight,” Welch told NBC Chicago in an interview.

After the vote last week, the 11 CTU-aligned board members who voted in favor of the budget penned a letter to King, obtained by the Tribune, asking for her to meet with a small group of members to discuss “a coordinated Springfield strategy.”

“Financial risks must be communicated responsibly, but always alongside the district’s plan and the opportunity to build on recent momentum with Springfield leaders,” they wrote.

The seven members who opposed the budget amendment fired back, arguing in their own letter to King that such a meeting would “intentionally limit board access to information.” They instead asked her to call a special board meeting open to the public.