Senate Democrats plan to stay on the Senate floor all day Monday and into the night to argue against the confirmation of education secretary nominee Betsy DeVos, who is expected to win approval at noon on Tuesday.

Senate rules require 30 hours of debate on DeVos unless both parties agree to yield time back. But Democrats are refusing to yield back time and will talk for hours against DeVos, a wealthy GOP donor and school choice advocate.

Democrats took to the Senate floor shortly after noon Monday to condemn the nomination, and accused DeVos of harboring views in opposition to public education and having business interests that will lead to endless conflicts of interest if she takes the helm at the Department of Education.

All Democrats plan to vote against DeVos, along with Sens. Susan Collins, R-Maine, and Lisa Murkowski, R-Alaska. Democrats hope to attract a third Republican opponent to her nomination, which would leave DeVos one vote shy of winning confirmation.

"We need just one more Republican to join us," Sen. Patty Murray, R-Wash., said Monday. "To stand on the side of students and parents and public education in America and say no to Betsy DeVos."

Republicans who support DeVos say she is facing staunch opposition because of the activism of teachers unions, who always work to thwart charter schools and school vouchers that provide an option outside the public school system.

Democrats can talk until about noon Tuesday. That's when a vote is scheduled for DeVos.

With 50 Republicans supporting her, DeVos is expected to need Vice President Mike Pence to cast a tie-breaking vote.

"The Vice President will be available if we need him," Majority Leader John Cornyn, R-Texas, told the Washington Examiner.