Advocates have filed an initiative petition to impose limits on campaign contributions for candidates in Portland City Council elections.

The petition, filed Dec. 20 by Ron Buel and B. Elizabeth Trojan, needs 34,156 signatures by July 6 to successfully make it to the ballot in November 2018.

The proposal would limit individual contributions to $500 per candidate per year, and cap a person's aggregate donations at $5,000 each year. A small donor committee that only accepts donations of $100 or less could contribute as much as it wants to any candidate. Political Action Committees would have to follow the same rules as individual donors.

The state of Oregon has no campaign finance limits—making big-ticket races an expensive proposition. Portland Mayor Ted Wheeler, for example, raised about $1.1 million in his 2016 campaign.

But Portland City Council has already passed a public campaign finance program that will, starting in 2020, allow candidates to accept city dollars if they agree to a donation cap.

The initiative would make Portland's campaign finance rules more like Multnomah County's regulations.

Last November, voters passed a spending cap in county races, limiting direct contributions from any individual or group to $500, limiting independent expenditures to $5,000 per individual and $10,000 per group, and requiring ads to list the five biggest sources of funding.

The Multnomah County rules are being reviewed in court.

The petition says that limiting campaign contributions would open up elections and allow "a greater diversity of persons to seek office" while reducing the "reality and appearance of corruption."