Eleven alderpersons called a special meeting in an effort to pressure the mayor to revise the mandate that requires all city employees to be vaccinated against COVID-19.
The deadline to get the first dose was Sunday.
City data shows more than 20 percent of Chicago police officers are not complying with the mandate.
Lightfoot is calling the meeting a stunt and released a letter, reading in part:
"We have lost over 7,500 Chicagoans over the course of the pandemic, and the only way to stem the tide is increasing the number of people who are fully vaccinated. I, for one, will not participate in any more political stunts, but my administration will continue to be transparent and collaborative... as we have been throughout the pandemic."