Senate Majority Leader Harry Reid (D-Nev.) forced Senators to return to the floor for a rare live quorum call Monday evening in a move that hints at the potential procedural showdown this week over financial regulatory reform.

The call was issued shortly after the Senate voted 57-41 against taking up the regulatory reform bill “to highlight just how important this issue is,” according to a Reid spokeswoman. The spokeswoman added that the rarely used procedural move was also used to illustrate Republican obstruction to other issues, such as long-delayed nominations, though Reid did not mention any of these issues on the floor.

Reid last called a live quorum — during which the Sergeant-at-Arms is authorized to request that Members come to the chamber — while the Senate was in a stalemate over extending unemployment benefits in March. Reid used the rare procedural tool then to discuss how best to proceed on the issue, but Monday’s quorum call was simply to “apply a little pressure” to Members and serve as a warning for the potential debate over regulatory reform that will likely consume the floor this week, his spokeswoman said.

The debate over financial regulatory reform has grown increasingly partisan in recent weeks. The heated rhetoric even prompted Reid to issue an apology to Minority Leader Mitch McConnell (R-Ky.) Monday afternoon. In a floor speech, Reid noted that he has “criticized the Republican leader for the way he was handling Wall Street reform.” But, Reid said, “I want the record to be very clear, however, I was in no way impugning the integrity of my friend from Kentucky.”

The apology was not exactly a call for detente, however. Reid went on to criticize Republicans for stalling progress on financial reform and is expected to continue using procedural tactics this week to showcase GOP opposition. Reid has already filed another motion to force a vote on the financial reform bill.