A left-leaning dark money group could go up with the first Democratic-allied Iowa ads as early as this weekend, just as Hillary Clinton, the party’s presidential frontrunner, called for an end to “unaccountable” money in politics.

Americans United for Change is a “social welfare” nonprofit headed by Brad Woodhouse, a former communications director at the Democratic National Committee who worked on both of Obama’s presidential campaigns. Woodhouse is also president of American Bridge, a super PAC that produces opposition research for Democrats.

Americans United for Change is looking into ad times during Face the Nation this Sunday, according to a document filed at KCCI, a CBS-affiliate in Des Moines. The document was surfaced using Sunlight’s political ad sleuth Iowa feed.

Americans United for Change didn’t immediately return a call, and the document doesn’t say what the ad would focus on.

The group has been tweeting at politicians and film industry members today to promote “our video exposing climate change deniers in Congress,” which is up for a Webby Award.

The request came a day before presidential candidate Hillary Clinton, the overwhelming favorite to win the Democratic nomination, came out against political spending by groups that do not disclose their donors.