Rep. Maxine Waters, D-Calif., is facing scrutiny from a conservative watchdog group for possibly violating fundraising rules in a slate mailer, with the group requesting that Waters’ campaign committee be audited as a result.

The Federal Election Commission received a complaint Monday from the National Legal and Policy Center claiming that Waters, her campaign, and a pro-charter school group called Families and Teachers for Antonio Villaraigosa violated federal election law. The complaint claims the group paid $25,000 for Villaraigosa to be featured in the Waters mailer when he was running for governor in the Democratic primary earlier this year.

Although candidates can pay a fee to be included in slate mailers, it’s illegal for outside groups such as Families and Teachers for Antonio Villaraigosa to make such a payment.

As a result, the group claims the payment was illegal and should be investigated. The group also has urged for an audit of Waters’ campaign committee.

Waters’ slate mailers have attracted backlash in the past, including earlier this year when the National Legal and Policy Center filed a complaint with the FEC against her due to a $35,000 payment to Waters’ campaign fund from the Democratic State Central Committee of California to feature now-Sen. Kamala Harris, D-Calif., in one of Waters’ slate mailers in 2016.

Villaraigosa lost the Democratic primary race to California Lt. Governor Gavin Newsom, who is going up against Republican businessman John Cox next month.

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