Des Moines — Elizabeth Warren is taking a shot at primary opponent Michael Bloomberg over the 45-day extension he's received to file his personal financial disclosure form to the Federal Election Commission. That delay will keep Super Tuesday voters from knowing whether the former New York City mayor has "serious conflicts of interest," Warren said in Des Moines on Sunday.

"If he has entanglements with China, serious conflicts of interest, business interests in other parts of the world or with other corporations, when do we get to know about that? Not until after Super Tuesday," Warren said. "That is not how democracy is supposed to work, and we need to shut that down."

Bloomberg, a billionaire whose estimated worth exceeds $50 billion, has bet big on Super Tuesday, March 3, when most of the states are slated to vote or caucus. He has spent eight figures in delegate-heavy Texas and California and over $1 million in every other one of the March 3rd states — except Warren's and Bernie Sanders' home states of Massachusetts and Vermont.

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He will not be on the ballot on any of the first four states. Because Bloomberg will be allowed to delay handing over his financial disclosures to the Federal Election Committee until late March, Democratic voters in these states will head to the polls and caucuses without knowing just how much Bloomberg is worth and in which interests he currently has investments. He is not the first candidate to be granted an extension, but he is the only one who will not have made his disclosures before voting begins.

Since he entered the 2020 race, Warren has often used Bloomberg as a foil, pointing at his flood-the-airwaves strategy as an example of the corrupting influence of money in politics that she wants to root out. She has also long called for more transparency in federal elections, specifically saying that every candidate for federal office should be required to release their tax returns. She has also joked that Bloomberg decided to run because he fears she'll win and he would be subject to her wealth tax.

"You may have heard there are some billionaires who don't like this plan," Warren said at an earlier town hall Sunday. "Some have cried [...] Others ran for president, figured it was cheaper than paying a wealth tax."

For her part, Warren released her tax returns dating back to 2008. After Pete Buttigieg, who has released his tax returns going back to the same year, called on Warren to make public older records that include more of her private-sector legal work, she posted an additional compilation of the compensation she received for over three dozen individual cases.

Tim Perry contributed to this report.