Chicago (CBS) — A new public school in Dunning came with promises those who live nearby could attend. Now, those families are finding out the school may not benefit them at all.

They’re not the only ones who feel blindsided. The alderman, who made those promises about Taft High School’s new annex, does too. He said Chicago Public Schools told him one thing and then did a last minute about-face.

Before a shovel even broke ground for Taft’s new freshman building and academic center on the city’s Northwest Side, Ald. Nicholas Sposato promised a “100 percent new school”.

That guarantee, as of this week, is now no more.

“So, the agreement got changed to be candid,” Sposato said.

It leaves families of kids at four schools furious.

“I feel betrayed,” Joe Gentile, Jr., a Canty School parent, said. “I’m not saying the alderman is lying. I believe he was misled.”

Not everyone is so sure. But, Ald. Sposato insists he struck a deal with CPS several years ago, allowing the freshman building to be built in his ward and then feed into Taft, in another ward, if his constituents’ kids could attend.

“Unfortunately, I never got anything in writing,” Sposato said.

Parents like Eunice Smith said they took Sposato and a CPS official on their word, preferring Taft over their neighborhood high school, Steinmetz.

“I am a mother of five children, one who had a very negative experience at Steinmetz,” Smith said. “It’s not an option.”

In a city where so-called “good” public high schools are considered scarce commodities, this last minute change leaves dozens of families scrambling.

A CPS source said students at the four impacted schools may attend the new school if there’s room. But, Taft is overcrowded now.

Overcrowded or not, Sposato vows to make it right.

Sposato would not give CBS 2 the specific names of who in CPS’s prior administration allegedly agreed to this deal. A CPS spokesperson did not directly address this flap, only stating they’ll work with families to ensure this new school enhances academic opportunities for all area students.