San Francisco voters will consider on Tuesday a ballot measure that would further enshrine abortion access in the liberal stronghold — including through a contentious provision that would require the city to post signs in front of faith-based pregnancy resource centers that refer visitors to other clinics where abortions are offered.

The ballot measure, called Proposition O, would require the city’s public health department to post signage outside of pregnancy resource clinics notifying visitors that they don’t offer abortions and a list of clinics that do offer them. The proposal also would require the city to maintain a public website with similar abortion-related information. The ballot measure, introduced and supported by the city’s Democratic mayor, London Breed, faces staunch opposition from Catholic groups and churches.

While the Office of the Controller estimates the signage will cost the city up to $8,000 a year, the cost could be higher as legal challenges are expected if the measure passes. The Supreme Court has already struck down a similar California statewide law called the “Reproductive FACT Act,” which required religious pregnancy clinics to advise women about abortion and birth control options, as a likely First Amendment violation.

As San Francisco voters consider the ballot proposition on Tuesday, a slew of abortion-related measures are on state ballots across the country — in Arizona, Colorado, Florida, Maryland, Missouri, Montana, Nebraska, New York, Nevada, and South Dakota. 

In the seven states that have already voted on abortion measures since the overturn of Roe v. Wade in 2022, the side supporting abortion access has won in all seven states, making the issue a major part of the Democratic platform as the party hopes the issue will drive voters to the polls. Vice President Harris has amped up abortion rhetoric in the weeks leading up to the election, recently holding an event in Texas to highlight the state’s strict abortion laws.

NBC News’ final presidential campaign polling, released this weekend, indicates that Ms. Harris’s biggest advantage in the election is abortion, as 53 percent of registered voters trust her to deal with abortion compared to only 33 percent trusting President Trump. When it comes to other issues such as inflation and immigration, Trump leads by wide margins. 

San Francisco’s Proposition O also aims to create a Reproductive Freedom Fund to support abortion services and reproductive rights, change zoning law so that abortion clinics can operate in more areas, and prohibit city officials from providing information to law enforcement agencies of other states or the federal government concerning a patient’s pregnancy status or whether she gets an abortion. 

Ms. Breed, who has been vocally supporting the measure, said in a press conference that pregnancy resource centers in the city are “misleading” to vulnerable women and that the city needs to use “every resource that San Francisco has” to protect abortion access. Abortion is already heavily protected in the state, as it is allowed anytime until viability and “at any time” to protect a woman’s life or health. California also allows nonresidents and people of any age, including minors, to legally obtain abortions.

The Catholic Church has been vehemently opposing the measure, saying that it will “stigmatize” the pregnancy resource centers and endanger the clinics’ employees, volunteers, and clients. 

The Archdiocese of San Francisco argues it is unnecessary as California is already a “sanctuary state” for abortion and says taxpayer funds shouldn’t be used to instill signage “outside life-affirming healthcare and pregnancy support centers, singling them out as facilities that refuse to perform abortions and potentially opening them up to abusive behavior by opponents.”

“Why doesn’t Proposition O require the city to install signage outside facilities that do abortions to direct women to places where they will be supported in giving birth?” the archdiocese said in a statement. “Do the proposition’s authors truly believe in choice?”