Democrats intensified their attacks on Sen. Jim Bunning (R-Ky.) and his allies Friday, denouncing his filibuster of a temporary extension of unemployment benefits and calling on the GOP to help pass the measure.

Starting Wednesday, Bunning undertook a largely one-man filibuster of legislation that would extend a series of unemployment, transportation and other programs until March 28. Bunning is demanding the Senate include language that would pay for the spending.

Bunning’s filibuster, which by Friday morning was picking up support from some Republicans like Sen. Bob Corker (Tenn.) and National Republican Senatorial Committee Chairman John Cornyn (Texas), enraged Democrats, particularly Majority Whip Dick Durbin (Ill.).

Durbin’s frustration quickly spread to other Senate Democrats, with several denouncing the filibuster Friday.

“If you do not relent, these benefits will expire Sunday,” Environment and Public Works Chairman Barbara Boxer (D-Calif.) wrote Bunning on Friday. “Unemployment insurance is a lifeline to the long-term unemployed whose families have been hit very hard by this recession.”

On the other side of the Capitol, Speaker Nancy Pelosi (D-Calif.) praised Democrats’ efforts to break the logjam.

“It is really hard to understand why one Senator in the United States Senate is holding up the extension of unemployment insurance at this time. But he is. And I am pleased that the Senate Democrats are trying to make a move to dislodge that,” Pelosi said.

While Democrats kept their criticism centered mainly on Bunning, the Democratic National Committee on Friday sought to hang the filibuster on the heads of all Republicans.

“Last night we discovered just how far Republicans will go to stop the work of the American people for pure politics — even at the expense of our citizens’ health and economic security,” DNC spokesman Brad Woodhouse said in a statement.

Even some Republicans were becoming increasingly uncomfortable with Bunning’s filibuster. Environment and Public Works ranking member James Inhofe (Okla.) told the Tulsa World on Friday that he was “going to call in all my chits” with Bunning in the hopes of breaking the filibuster, in part because it will result in the furloughing of federal highway employees starting Monday.