Tempe City Council will vote next month on whether to send a ballot measure to voters next March seeking tighter restrictions on independent expenditures.

The Sunshine Ordinance would require groups making independent expenditures over $1,000 to disclose their organization name and source of funding. Tempe has not seen an uptick in independent expenditures yet but wants to prevent a future increase as independent expenditures are often associated with mud-slinging and attack ads.

The Mayor’s office and the Tempe Chamber of Commerce have expressed concern over the Sunshine Ordinance, worrying it might cause legal trouble for the city for infringing on first amendment rights and the Citizens United decision.

Even if the measure is approved by voters, as a charter amendment it will be automatically reviewed by the state to ensure there is no conflict with state law.