WASHINGTON (AP) ― President Barack Obama and the top Republican in Congress swapped barbed political charges on Wednesday yet carefully left room for further negotiations on an elusive deal to head off year-end tax increases and spending cuts that threaten the U.S. economy.

Republicans should “peel off the war paint” and take the deal he’s offering, Obama said sharply at the White House. He buttressed his case by noting he had won re-election with a call for higher taxes on the wealthy, then added pointedly that the nation aches for conciliation, not a contest of ideologies, after last week’s mass murder at a Connecticut elementary school.

But he drew a quick retort from House of Representatives Speaker John Boehner when the White House threatened to veto a fallback bill drafted by House Republicans that would prevent tax increases for all but million-dollar earners. The president will bear responsibility for “the largest tax increase in history” if he makes good on that threat, the Republican leader declared.

In fact, it’s unlikely the legislation will get that far as divided government careens into the final few days of a struggle that affects the pocketbooks of millions and blends lasting policy differences with deep political mistrust.

Boehner expressed confidence the Republicans’ narrow so-called Plan B bill would clear the House on Thursday despite opposition from some conservative, anti-tax dissidents, but a cold reception awaits in the Democratic-controlled Senate.

As for a broader agreement, officials said there had been little if any progress toward closing the gap between the two sides in the past two days, even though aides to the president and Boehner have remained in contact.

On paper, the two sides are relatively close to an agreement on major issues, each having offered concessions in an intensive round of talks that began late last week.

But political considerations are substantial, particularly for Republicans.

After two decades of resolutely opposing any tax increases, Boehner is seeking votes from fellow Republicans for legislation that tacitly lets rates rise on million-dollar income tax filers. The measure would raise revenue by slightly more than $300 billion over a decade than if all of the Bush-era tax cuts remained in effect.

But Boehner’s office trumpeted another figure ― an estimate that claimed it would amount to a tax cut of nearly $4 trillion compared with what would happen if all those tax cuts were to expire as scheduled with the turn of the year.

Similarly, despite vehement protests that the looming across-the-board spending cuts would seriously affect the Pentagon, the leadership’s fallback bill does nothing to blunt or eliminate the reductions scheduled to begin on Jan. 1

Republican Congressman Tom Rooney, a member of the Armed Services Committee, said he will vote for the legislation even if it leaves the defense cuts in place. He said if he didn’t vote for a bill that prevents a tax increase for 99 percent of people “I’m not doing my job.”

That appeared to be the hope of Boehner and the rest of the leadership, that by showing his rank and file is united behind the fallback bill, the speaker would be in a strong position to demand concessions from the White House in the broader endgame.

Democrats had their own issues, but so far, they have remained largely submerged as Republicans struggle.

At the White House, Obama repeated that he is ready to agree to spending cuts that may cause distress among some fellow Democrats, but he saved his sharpest words for Republicans.

“Goodness, if this past week has done anything, it should just give us some perspective,” he said in a reference to the shootings of school children in Connecticut.

Yet even as he implored Republicans to “take the deal,” he made it clear he’s open to more bargaining.

Asked whether he might be flexible on the level at which tax rates should rise, he said he wasn’t going to bargain in public. He also addressed the issue of politics.

Speaking of Republicans, he said, “It is very hard for them to say yes to me. But at some point, they’ve got to take me out of it.”

Boehner did not slam the door on further compromises in his brief appearance before reporters. “Republicans continue to work toward avoiding the fiscal cliff,” he said.