A leading Senate liberal on Tuesday refused to back down from his threat to filibuster the White House's deal on tax cuts after President Obama lashed out at the left for opposing it.

Sen. Bernie Sanders (I-Vt.), a self-described democratic socialist, expressed confidence he would win in a showdown with the White House over the expiring Bush tax cuts.


"The American people don't want this agreement. Our job is to get a handful of Republicans on board [to defeat this proposal]," he said on MSNBC. "I'll do whatever it takes, certainly including a filibuster, to defeat this proposal."

Sanders repeated his filibuster threat following Obama's afternoon press conference at the White House where he defended the plan against criticism from the right and left.

Obama accused liberals of expressing "sanctimonious" outrage over the agreement to extend all the tax cuts, including those for the wealthy, for two years. He also compared Republicans to "hostage takers" for blocking an extension of the middle-class tax cuts only. 

The president called the press conference in an attempt to head off criticism from members of his own party in Congress who have threatened to derail the compromise. 

"This country was founded on compromise," Obama said.

Sanders said that there is no guarantee that the tax cuts for the wealthy would go away when they expire again in two years, making the deal an even more bitter pill to swallow.

"I think this is very bad public policy ... it's bad politics as well," he said. "What makes you think in two years, that is going to change?"