Senate leadership is working to lock in an agreement to pass a sweeping defense bill on Wednesday, after Republicans blocked the bill earlier this week, throwing it into limbo.  

Democrats and Republicans are running a "hotline" — where they check with all 100 senators to see if anyone would block the deal — to hold votes Wednesday on 21 amendments to the National Defense Authorization Act, a source confirmed to The Hill. 

After the votes on the 21 amendments, the Senate would then vote on final passage of the defense bill, the source added.  

In a win for Republicans, the package of amendments includes a proposal from Sen. James Risch (Idaho), the top Republican on the Foreign Relations Committee, that would impose sanctions on the Nord Stream 2 pipeline, a Senate aide told The Hill.  

That's a shift from the initial package of 18 amendments that leadership tried to get a deal on before the Thanksgiving recess. That package did not include an amendment related to the Nord Stream 2 pipeline, with the Biden administration urging members to block the amendment.  

Risch and Sen. Ted Cruz (R-Texas) were among the Republicans who blocked the smaller amendment package before the Thanksgiving recess because their Nord Stream 2 proposal wasn't included.  

Republicans then blocked the defense bill from advancing on Monday night, arguing that Senate Majority Leader Charles Schumer (D-N.Y.) wasn't giving them the chance to get votes on the amendments they wanted. 

"It is especially bizarre to see the Democratic leader so focused, so intent, on blocking the Senate from dealing seriously with the growing aggression from Putin’s Russia. He seems downright desperate to block new bipartisan action on Nord Stream 2. It’s strange to see," Senate Minority Leader Mitch McConnell (R-Ky.) said on Tuesday. 

He added that if the GOP amendment could be "improved with modifications, then by all means, let’s have a public debate." 

McConnell, according to GOP senators, backed the demand for a vote on Nord Stream 2 sanctions as part of the Senate's debate on the defense bill. The House also included an amendment in its version of the defense bill to require the mandatory sanctions on the pipeline. 

The potential deal is a shift from Monday night, when the defense bill appeared to be stuck in limbo after Republicans blocked it.

But senators indicated throughout Tuesday that they were continuing to swap offers in hopes of breaking the logjam. 

"We just got a new offer from the Dems. We sent them an offer earlier today ... and so I'm hopeful that we'll get something that will enable the process to move forward," said Sen. John Thune (S.D.), the No. 2 Senate Republican.  

Asked about Republicans wanting an amendment vote related to Nord Stream 2, he added, "That's a big one."