Even as a bipartisan task force began trying to reach a deal on tax cuts Wednesday, Democrats and Republicans in Congress made it clear that neither side has any interest in compromise.

Fresh out of a Tuesday White House meeting aimed at forging a bipartisan path, Senate Republican leaders announced Wednesday that their entire 42-member Conference will block any bills from coming up until votes are taken on extending Bush-era tax cuts and keeping the government funded.

“We will not agree to invoke cloture on the motion to proceed to any legislative item” until those two issues are done, Republican Senators wrote in a letter to Senate Majority Leader Harry Reid (D-Nev.). “With little time left in this Congressional session, legislative scheduling should be focused on these critical priorities.”

President Barack Obama dismissed the idea that the GOP ultimatum breaks the spirit of Tuesday’s bipartisan, bicameral huddle.

“There are going to be some lingering politics” that will have to work themselves out, the president told pool reporters Wednesday. “There are going to be some ups and downs in this process,” but a tax cut deal will ultimately come together, he said.

Reid was less diplomatic in his response, accusing GOP Senators of continuing to “stand on the sidelines rooting for failure.”

But Democrats have been itching for a tax fight in the hopes of forcing votes on extending middle-class tax cuts, an issue that plays well around the country given the shaky state of the economy.

The White House has tried to move the issue forward by tapping Treasury Secretary Timothy Geithner and Office of Management and Budget Director Jacob Lew to lead a new bipartisan, bicameral team, which met for the first time Wednesday, to find common ground on the issue.

But the boldness of Republicans announcing unilateral opposition to legislating until they can extend cuts for all taxpayers, including the wealthy, has left many Democrats stunned.

“They’re blocking the most stimulative thing for the economy for the least stimulative thing for the economy: tax cuts for millionaires and billionaires,” Sen. Claire McCaskill (D-Mo.) said from the floor.

Finance Chairman Max Baucus said he still intends to push at least one vote on a stand-alone middle-class tax cuts bill, similar to the measure the House is expected to vote on today.

“It’s important to have a vote on middle-class tax cuts” to show where the two parties stand, the Montana Democrat said.

But that vote and a potential vote on a GOP-backed permanent extension of all of the Bush tax cuts appear to be the only message votes that Senators will take on the matter.

The final tax package will likely extend all of the Bush tax cuts for at least two years, according to Senate Democratic and Republican aides. And while the final bill will likely include a handful of Democratic priorities, such as extending unemployment insurance and other jobs measures, the fact that it will extend tax cuts for the wealthy means Republicans will be seen as the big winners of the fight.

Sen. John Kerry drew parallels in his battle with Republicans over climate change legislation, which went down in a hail of partisan fire earlier this year. The Massachusetts Democrat said the GOP tactic is to get Democrats to capitulate to GOP demands and call it compromise.

“Look at last year with the energy bill. We compromised and compromised. But there was zero compromise on their part,” he said.

Meanwhile, House Democratic leaders are moving forward today with a vote on their own middle-class tax cuts bill. House Majority Leader Steny Hoyer said Wednesday that the bill may appear to be out of step with the Senate, but the issue warrants a vote.

“One of the frustrations the American public has is that we do not even pass things on which we agree because there are things on which we don’t agree that hold us hostage, create filibusters, create delay and obstruction, and rightfully the American public is frustrated by us not being able to do even things on which we have consensus,” the Maryland Democrat told reporters. “I am hopeful that common ground will be reflected tomorrow in that vote.”

The forced vote on the issue leaves some House Republicans scrambling over what to do because they traditionally support tax cuts. Even GOP leaders are switching positions on the issue in order to defend the principle that the vote should include an extension of tax cuts for the wealthy.

Rep. Dave Camp, the presumptive chairman of Ways and Means Committee in the 112th Congress, told the Associated Press in July that it would be difficult to block a bill extending middle-class tax cuts, even if it didn’t stop tax rates from increasing for high earners.

“I’ll probably vote for it myself,” the Michigan Republican said at the time.

But asked Wednesday whether he would support the stand-alone middle-class tax cuts bill headed to the floor Thursday, Camp said, “In principle, I think that we should not decouple the tax issues, and I would maintain that position.”

Speaker-designate John Boehner (R-Ohio) is also expected to vote against Thursday’s bill, despite saying in September on CBS’ “Face the Nation” that, “If the only option I have is to vote for those at $250,000 and below, of course I’m going to do that.”

A Boehner aide said the GOP leader’s current stance reflects his “pledge to America to permanently stop all of the tax hikes — and that’s what we’ll fight for.”