Betsy DeVos cleared a major hurdle in the Senate Friday in her bid to become the next Education secretary – but likely will need Vice President Pence’s help getting over the finish line next week.

The billionaire Republican donor and school choice activist has emerged as one of President Trump’s most controversial Cabinet nominees, with two Republican senators having announced they will join Democrats in opposition on the final vote.

Both those senators – Susan Collins of Maine and Lisa Murkowski of Alaska – went along with advancing her nomination early Friday morning by voting to end debate. The 52-48 vote was along party lines.

But multiple Senate sources tell Fox News they expect the final confirmation vote, coming as early as Monday, to split 50-50 – with Collins, Murkowski and all 48 Democratic senators voting against DeVos.

This would put the pressure on Pence to cast a historic tie-breaking vote.

DeVos supporters indeed are expecting Pence to do so, giving the nominee the necessary 51 votes to win confirmation. If he does, it would mark the first time in history a vice president has voted to break a tie to confirm a Cabinet officer.

The procedural gymnastics come as the Trump Cabinet confirmation process gets increasingly tied up in a complex partisan battle, related not only to the nominees themselves but some of Trump’s more controversial executive actions and simmering resentment over the way Republicans treated nominees under the Obama administration.

DeVos, though, has come under fierce criticism from labor unions, who accuse her of seeking to dismantle public education, given her history promoting charter schools.

Senate Minority Leader Chuck Schumer of New York calls her "one of the worst nominees."

"Ms. Devos does not deserve to be secretary of education," he said.

At Tuesday’s Senate education committee meeting on the nomination, Republican Chairman Lamar Alexander chided his Democratic colleagues.

“I believe their concerns are misplaced,” he said, arguing DeVos’ stance on the role of the federal government in local school systems aligns with what an overwhelming majority of senators voted for in replacing the controversial No Child Left Behind law in 2015.

The Tennessee senator urged colleagues to let the new president “have his Cabinet choice.”

A tie-breaking vote by the vice president would be rare on any matter, let alone a Cabinet pick.

The VP has not cast a tie-breaking vote at all in almost nine years. Then-Vice President Biden did not cast any such votes; then-Vice President Cheney was the last to break a tie, in a budget resolution vote in March 2008.

Fox News’ Chad Pergram and The Associated Press contributed to this report.