Businesses would be required to offer employees paid sick days under a new version of a controversial bill the City Council is planning to introduce today.

The primary change in the proposal initially brought forward in the fall is the definition of a small business, which is defined as having fewer than 20 employees instead of fewer than 10 – a concession to major backlash from the business community in recent months.

The legislation would require small businesses to pay full-time workers for up to five sick days annually.

Larger companies would have to offer up to nine days for full-time employees, according to a draft obtained by The Post.

The liberal Drum Major Institute and Working Families Party strongly support the bill, sponsored by Councilwoman Gale Brewer (D-Manhattan), and Drum Major released a study showing the benefits of a similar law in San Francisco.

Employment in San Francisco fell by only 3 percent – compared to 5.2 percent in five neighboring counties – from December 2006, right before the regulation took effect, until December 2009, the DMI report said.

Councilman Vincent Ignizio (R-S.I.) slammed the proposal, saying “additional burdens and unfunded mandates placed on small private businesses by government will only cause more to fail and make our economic woes worse.”