Reid: Senate vote on Lew expected this week

GOP senators have questioned Lew's private-sector experience with both Citigroup and New York University, and the former White House chief of staff's role in previous fiscal negotiations.

But Lew's nomination has not sparked the kind of criticism that another of President Obama's high-profile nominees, Chuck HagelChuck HagelLobbying World Ex-Dem leader: Clinton should include GOP in Cabinet Even Steven: How would a 50-50 Senate operate? MORE, has received. The Senate is expected to hold a procedural vote Tuesday on Hagel's nomination for Defense secretary.

Democrats have said that Lew has been exceedingly transparent during his nomination process, and believe he should be confirmed without issue.

Obama nominated Lew to replace Timothy Geithner, who left the Treasury Department in January.  

Sen. Orrin HatchOrrin HatchSenate GOP: National museum should include Clarence Thomas Mnuchin's former bank comes under scrutiny Trump’s economic team taking shape MORE (Utah), the ranking Republican on the Finance panel, declined to say Monday how he would vote on Lew's nomination. 

But Hatch did say that, if Lew cleared the committee fairly easily on Tuesday, he didn't see any reason to slow walk the nomination.

"If he comes out of committee, I don't see any reason why anybody would want to continue to put it off," Hatch said. "I can't speak for all my colleagues. All I can say is, we'll see what happens in committee tomorrow."

Sen. Jeff SessionsJeff SessionsCould bipartisanship rise with Trump government? Top Dem signals likely opposition to Sessions nomination #NeverTrump can love him or hate him, Trump always wins MORE (R-Ala.), perhaps the chamber's most vocal critic of Lew, continued to blast the nomination on Monday, saying Lew did not have the "gravitas" to be a good Treasury secretary.

But Sessions would not say whether he would push to delay a full Senate vote on the nomination. 

This post was updated at 6:45 p.m.