Mayor Lori Lightfoot, left, and Black Caucus Chair Ald. Jason Ervin (28). [Heather Cherone/The Daily Line]

The final full City Council meeting of 2019 promises to showcase a truly rare occurrence: a knock-down, drag-out floor fight with no clear projected winner.

Ten aldermen defied Mayor Lori Lightfoot Tuesday and sent a measure that would prohibit the sale of pot in Chicago until July 1 in order to ensure that firms owned by people who were hurt by drug laws can profit from the sale of cannabis.

That vote sets up a rare showdown between Chicago’s mayor and Chicago’s aldermen, who have more often served as a rubber stamp than an independent legislative body with its own set of priorities.

Related: Aldermen advance six-month ban on weed sales because lack of Black dispensary owners

If the measure passes over the mayor’s objections, that could trigger the first mayoral veto since 2006 — and perhaps triggered a full-scale rebellion by those already angered by the mayor’s decision to create a website — chicagobudgetvotes.com — to blast aldermen who voted against her 2020 spending plan.

At the same time, aldermen are braced for Lightfoot to renew her effort after the holidays to roll back aldermanic prerogative by attempting to rewrite the city’s zoning code — and perhaps looking for an opportunity to remind the mayor that a majority of the City Council makes laws for the city.

Related: At 6-month mark, Lightfoot’s effort to scale back aldermanic prerogative a work in progress

Ervin’s measure is not the only marijuana-related proposal on the agenda for the City Council meeting set to start at 10 a.m. Wednesday.

Aldermen will also weigh (O2019-8484) which would allow cannabis company Cresco Labs to relocate its MedMar dispensary from a 900-square-foot office at 3812 N. Clark St. to the 5,000-square-foot former home of the bar John Barleycorn at 3524 N. Clark St.

Related: ‘Give the brothers a piece:’ Aldermen narrowly OK dispensary amid criticism over lack of Black owners

That proposal advanced on a 7-5 vote Dec. 10 after an hour-long debate also centered on whether proposals from firms owned by Black and Latino entrepreneurs should be allowed to advance.

On firmer ground is another attempt by Lightfoot to push through another ethics reform measure designed to fulfill her central campaign promise to clean up city government and root out corruption. 

Aldermen are set to advance a measure that would ban them from working as lobbyists to press other elected officials on city-related matters.

The measure (O2019-8541), which has 31 co-sponsors, is set for a final vote despite several aldermen saying they were concerned it would open the city up to litigation. They also said it was unnecessary, even amid the federal investigations swirling around City Hall and the State Capitol.

The ban was prompted by the arrest of former State Rep. Luis Arroyo (D-Chicago) in October on charges that he allegedly offered to bribe a state senator by paying him $2,500 a month in exchange for the senator’s support on legislation that would benefit a client he was working for at the city level. But that state senator was wearing a wire for the FBI.

Related: ‘The feds are all around us:’ Ban on aldermen working as lobbyists advances despite concerns

In addition, the proposed city ordinance bans elected officials who represent other jurisdictions from lobbying city officials or city agencies. 

The ordinance carves out an exemption for elected officials who are also lawyers representing clients who have asked Chicago officials or agencies for an official action and are required to register as a lobbyist under state or local laws.

Aldermen on Wednesday are set give final approval to a number of items:

  • O2019-9121 — A measure authored by Ald. Matt O’Shea (19) that would allow aldermen to use their aldermanic office budgets to host document shredding and electronic recycling events.
  • O2019-9252 — A measure authored by Ald. Raymond Lopez (15) that would allow aldermen to use their expense accounts — which will grow by $25,000 in 2020 — to publish “an annual calendar regarding citywide and ward specific information, events and holidays.”
  • Twenty-three budgets for Special Service Areas across the city, including the approximately $300,000 budget for the Six Corners Special Service Area (O2019-7765), which was the source of controversy after Ald. Jim Gardiner (45) said he would vote against the budget unless the organization’s bylaws were changed.
  • Eighteen appointments to the boards of Special Service Areas across the city.
  • O2019-8545; O2019-8548; O2019-8556 — Three property tax breaks for commercial developments in the 14th, 21st and 11th wards.
  • O2019-9126 — A measure authored by Ald. Tom Tunney (44) that will allow the plaza outside Wrigley Field to operate through March 29 as negotiations over a long-term agreement continue.
  • O2019-9127; O2019-9128 — Two measures to ban home-sharing services in the 26th and 15th precincts of the 13th Ward.
  • O2019-8528 — A measure authored by Ald. Silvana Tabares (23 )to ban home-sharing services in the 35th precinct of the 23rd Ward.
  • Seven measures regarding the sale of packaged liquor.
  • O2019-6853 — A proposal by the Chicago Housing Authority to build an 80-unit addition to the Chicago Housing Authority’s Edith Spurlock Apartments at 2604-2742 N. Sheffield Ave. in the 43rd Ward.
  • O2019-8478 — A proposal by Marquis Capital to build a four-story mixed-use building with six residential units and ground-floor commercial space at 1057-59 W. Taylor St. in the 25th Ward.
  • O2019-7963 — A proposal by Joseph Perillo to build a 131-stall parking garage at 6301 N. Western Ave. in the 50th Ward.
  • O2019-4103 — A proposal by Thomas McCauley to build a six-story mixed-use building with 35 residential units and ground-floor commercial space at 3347 N. Southport Ave. in the 44th Ward.
  • O2019-8476 — A proposal by Culver’s franchisee Justin Obreicht to build an 18-unit mixed-use building at 3500-02 N. Clark St. in the 44th Ward.
  • O2019-7967 —  Permission to allow the Ivy Hotel to install a retractable structure to enclose its existing rooftop terrace. The expansion triggers the city’s density bonus program, requiring a $101,500 payment into the Neighborhood Opportunity Fund.
  • O2019-9258; O2019-9255; O2019-9256; O2019-9257 — Four measures that would terminate four tax-increment financing districts early.
  • Or2019-513 — A payment of  $1.3 million to settle a lawsuit filed by the family of 18-year-old Tevin Jones-Rogers, who was killed in a crash during a 2017 police pursuit.
  • Or2019-512 — A payment of $1.2 million to settle a lawsuit filed by the family of 24-year-old Heriberto Godinez, who died in police custody in July 2015. 
  • Or2019-511 — A payment of $850,000 to settle a lawsuit that alleges Shaquille Gillespie was charged with a crime to cover up the fact that police officers used excessive force while arresting him in a West Side alley in March 2013.
  • Or2019-514 — A payment of $175,000 to settle a lawsuit brought by Gertrude Matanky, who was crossing La Salle Drive at Lake Street in a crosswalk outside City Hall when she was struck by a car driven by Chicago Police Officer Phillip Flannagan while he was on duty.
  • O2019-8005 — A measure to extend the Music Box Foundation’s $1 lease of a former South Shore fire station at 6843 S. Harper Ave. to allow its community center to remain open until 2026.
  • O2019-8017 — A measure to spend $100,000 from the Central Park Tax Increment Financing District to purchase property to expand a park at 724-726 N. Kedzie Ave. in the 27th Ward
  • Eleven sales of city property.