Senate Democratic leadership cautioned this afternoon that they are not breathing a collective sigh of relief just yet over the payroll tax deal.

At a late afternoon press conference, Senate Democrats waved the red flag, indicating that they believe the votes are not there for the deal to pass yet in the Senate.

They pointed their fingers at Republicans in the Senate who are "withholding their support" of the bill, as it was negotiated late last night by the conference committee.

Not one Senate Republican on the payroll conference committee has signed off on the agreement, objecting because they believe they were shut out of the final negotiations on the agreement.

"Senate Republicans are MIA," Sen. Patty Murray, D-Wash., said.

"This is a bipartisan agreement with good things for the American people," Reid said. "I send a simple message to my Republican colleagues: Let's get this done as quickly as possible."

"You have a situation where for once the House Republicans are negotiating a responsible package and standing by it, but the Senate Republican leadership seems to be linking arms with the far right," Sen. Chuck Schumer, D-NY., said.

The next step is for both houses of Congress to pass the agreement, starting with the House of Representatives. Reid said after the House votes tomorrow, the Senate will vote on the bill, likely tomorrow afternoon. The bill needs 60 votes to get through the Senate, meaning it can only pass with Republican support.

But Republican support in the Senate isn't the only thing Reid should worry about. Two Democratic Senators have already announced their intention to vote against the bill tomorrow.

Sen. Mark Warner, D-VA., announced on the Senate floor this afternoon that he'll vote against the payroll tax deal because of debt, and urged his congressional colleagues to "stop digging."

"I will be voting against the conference report when it comes to the floor of this body tomorrow," Warner announced on the floor today. "The payroll tax cut that's been proposed isn't being paid for. It will add $100 billion to the debt."

Sen. Joe Manchin, D-WVA., also announced on the Senate floor this afternoon the deal will not get his vote.

"I voted for the idea the first time around because I thought as it was proposed to me that it might protect more jobs or save jobs, but I don't think that we have seen much evidence that that's happened," Manchin said this afternoon. "So I decided to stop throwing good money after bad and stop jeopardizing Social Security."