(CBS) — Backers of a proposal to give all employees in Chicago paid sick days held a rally Thursday evening.

About two dozen worker rights advocates dropped off 25,000 signatures at Mayor Emanuel’s office at 4 p.m.

The group supports an ordinance that was introduced to the Chicago City Council this spring that calls for employers to give all workers — both full and part-time — at least five sick days a year.

The proposal followed the firing of a Whole Foods employee who stayed home with her son during the Polar Vortex, when many schools were closed.

The measure says employees would earn one hour of sick time for every 30 hours they work.

The days could be used for personal illness, preventive care or to care for family members.

An analysis by the Institute for Women’s Policy Research finds the cost to Chicago businesses would be $121 million per year.

Melissa Josephs, with the group Women Employed, says the benefits would outweigh that, in increased worker productivity and fewer illnesses in the office.

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