An effort to make political contributions in Arizona more transparent has officially begun.

On Wednesday, former Arizona Attorney General Terry Goddard, a Democrat, filed papers for the proposed constitutional amendment with the Secretary of State's office.

The “Stop Political Dirty Money Amendment” is an effort to eliminate large unknown donations in Arizona elections. The measure would require anyone who makes a campaign expenditure of more than $10,000 in a two-year election cycle to disclose all the sources of that money. Anyone who doesn’t would be subject to penalties.

Earlier this month, Goddard said the amendment would not affect anyone’s free speech as some have argued.

"Folks can get out there. They can say whatever they want, run commercials, run ads, whatever, even if they're unsavory. They do have a constitutional right to do that. What this is doing is establishing in the Arizona Constitution our right to know who's paying for it," Goddard said.

The campaign will need to gather more than 225,000 signatures by early July to get the constitutional amendment on the ballot for the 2018 election.