More than 100 Atlanta teachers have joined a federal age discrimination lawsuit claiming they were forced out of their jobs or otherwise penalized by an administration that cultivated an environment openly hostile to teachers over 40, according to a lawyer for the plaintiffs.

Atlanta Public Schools"vehemently denies these allegations and intends to vigorously defend against these claims. The case is still in its early stages and APS looks forward to proving that no such discrimination took place,” district spokeswoman Pat St. Claire said in a written statement.

More teachers could sign on in the coming weeks before a May 1 deadline to join the suit.

The suit targets teachers who lost their jobs amid a new administration's efforts to improve struggling Atlanta public schools.

"APS routinely keeps very close supervision on older teachers in hopes of finding something wrong, gives them worse evaluations than younger and less experienced teachers, reassigns them to schools that are more difficult to work in, tells them that they impact the budget and pension fund too much, and repeatedly makes demeaning and derogatory statements to its older teachers," the suit claims.

“We believe the proof is there. It's just a matter of us assembling it,” Lester Tate, an attorney for the plaintiffs, said.

The school district has denied it discriminated against older teachers and said in court filings that any adverse employment decisions were "the result of legitimate, non-discriminatory reasons."

More than 60 percent of Atlanta teachers were over 40 when Superintendent Meria Carstarphen was hired in 2014, a percentage that remained unchanged as of last year, the district said in court filings.