WASHINGTON (AP) – An election watchdog is filing a complaint alleging than an outside group founded by top political aides to Iowa Sen. Joni Ernst violated campaign finance law in its efforts improve the Republican’s chance of reelection next year. It comes after The Associated Press reported earlier this month that Ernst’s work with the political nonprofit Iowa Values to raise money and build an electoral “firewall” potentially violated campaign finance and tax law.

The complaint by the nonpartisan Campaign Legal Center requests that the Federal Election Commission launch an investigation. An attorney represent both Ernst and Iowa Values did not immediately respond to a request for comment.