As the House prepares to hold a pivotal vote Monday night on a Senate-passed payroll tax cut package that GOP leaders are urging members to oppose, Democrats are seeking to put GOP lawmakers on the spot by launching robocalls in 20 districts across the country.

(Joshua Roberts/BLOOMBERG)

The calls, which were recorded by Democratic strategist James Carville and launched by the Democratic Congressional Campaign Committee, target GOP lawmakers in 15 states.

News of the calls comes hours after House Speaker John Boehner (R-Ohio) announced that the House was prepared to vote down the Senate-passed package Monday night. House Republicans are arguing in favor of a one-year extension of the tax holiday and other provisions rather than the two-month deal that was negotiated by Senate Majority Leader Harry Reid (D-Nev.) and Minority Leader Mitch McConnell (R-Ky.).

McConnell, who on Friday and Saturday appeared to consider the Senate compromise a victory, by Sunday afternoon was backing up Boehner’s call for the House to reject the deal and for both chambers to work toward a longer-term plan.

It appears that not all Republicans are on board, however. Sen. Scott Brown (R-Mass.) issued a statement Monday morning blasting Boehner’s move as “irresponsible and wrong.”

“I appreciate (House Republicans’) effort to extend these measures for a full year, but a two-month extension is a good deal when it means we avoid jeopardizing the livelihoods of millions of American families,” Brown said. “The refusal to compromise now threatens to increase taxes on hard-working Americans and stop unemployment benefits for those out of work. During this time of divided government, both parties need to be reasonable and come to the negotiating table in good faith.”

And Sen. Dick Lugar (R-Ind.) said during an appearance on MSNBC Monday afternoon that the House should pass the Senate deal.

“At this stage, the whole thing could be jeopardized if there is a dispute between the House and Senate over the term of the extension, if it’s two months versus a longer extension. ... I’m very hopeful that that will not occur. I’m hopeful, maybe without basis, the House of Representatives will pass the bill the Senate passed and it will do so tonight,” Lugar said.

Sen. Dean Heller (R-Nev.) is also calling for the House to pass the two-month extension.

“What is playing out in Washington, D.C., this week is about political leverage, not about what’s good for the American people,” Heller said in a statement. “Congress can work out a solution without stopping the payroll tax cut extension for the middle class, jeopardizing seniors’ access to health care or threatening unemployment insurance.”

House Republicans are planning a 6 p.m. conference meeting at the Capitol – which raises the possibility that votes, originally scheduled for 6:30 p.m., could be pushed back if the gathering turns raucous. House Democrats are holding their own caucus meeting at 5 p.m.

What makes Monday’s vote somewhat unpredictable is the fact that members will be returning to Washington after spending the weekend in their districts, and some lawmakers may return more quickly than others. If all House members are present and all 192 Democratic lawmakers vote “yes” on the deal, Democrats would need only 26 Republicans to cross over in order for the measure to pass.

Thirteen of the lawmakers targeted by the DCCC calls are House GOP freshmen: Kevin Yoder (Kansas), Tim Walberg (Mich.), Renee Ellmers (N.C.), Jon Runyan (N.J.), Michael Grimm (N.Y.), Bob Gibbs (Ohio), Mike Kelly (Pa.), Pat Meehan (Pa.), Mike Fitzpatrick (Pa.), Kristi Noem (S.D.), Stephen Fincher (Tenn.), Jaime Herrera Beutler (Wash.) and David McKinley (W.Va.).

The other seven lawmakers are GOP Reps. Elton Gallegly (Calif.), Jerry Lewis (Calif.), Mike Coffman (Colo.), Bill Young (Fla.), Tom Rooney (Fla.), Tim Murphy (Pa.) and Joe Barton (Texas).

This post has been updated since it was first published.