If San Francisco voters pass a measure mandating community policing and foot patrols, that could prevent another item on the ballot, the mayor’s sit-lie ban, from taking effect.

The foot patrol measure includes a clause that voids the sit-lie ordinance if Mayor Gavin Newsom’s measure garners fewer votes.

“It has one purpose, and that’s to kill sit-lie,” Newsom said. Click here to listen.

The mayor said the measure approved for the ballot 7 – 4 on Tuesday by the supervisors is unnecessary because the police department already has a community policing plan.

“It’s everything to do with a poison pill to play politics with sit-lie,” Newsom said.

Supervisor David Chiu said the idea for the offending clause came to him via the mayor himself. Newsom included his own poison pill in another ballot measure that attempts to block a hotel tax increase from going into effect.

Chiu said it offers voters a “clear choice” for how deciding how the city should address crime and homelessness.