DES MOINES, Iowa (AP) — Democrats are preparing for what could be their most contentious debate yet.

The six candidates on the stage Tuesday night are all looking for a way to break out of the crowded pack at the top with just weeks to go until the Iowa caucuses.

Bernie Sanders, Elizabeth Warren, Amy Klobuchar, Joe Biden, Pete Buttigieg and Tom Steyer will all appear at the debate. The debate comes as Warren has confirmed a media report that Sanders told her in 2018 that he didn’t think a woman could win the election against President Donald Trump. Sanders has denied making that comment, calling it “ludicrous.”