Amid reports that House and Senate negotiators are close to a deal to avert a government shutdown, tea party activists are converging on the Capitol for a midday rally to press for deeper spending cuts and for defunding President Obama’s health-care reform.

“I think we’ll see a high level of excitement,” says Rep. Steve King (R) of Iowa, a featured speaker at Thursday’s rally. “It helps our leadership to have a strong showing so that Republicans and [Senate majority leader] Harry Reid sees that this is real.”

A key target for the rally is the ongoing negotiations over spending for the balance of the 2011 fiscal year. The latest continuing resolution will expire on April 8. Activists are also calling on Congress to defund Planned Parenthood and to remove some $105 billion in automatic funding for health-care reform that was written into the 2010 legislation – moves that Democrats strongly oppose.

Republicans campaigned to win back the House last year on a pledge to cut spending $100 billion below Mr. Obama’s 2011 budget request. That’s comparable to the $61.5 billion cut below current spending levels that the House passed on Feb. 19 and the Senate subsequently rejected.

After a meeting with Senate Democrats on Wednesday evening, Vice President Biden told reporters that both sides are now working off the same number: $73 billion in cuts off the president’s budget request, or $33 billion below current spending levels.

“There’s no reason why, with all that’s going on in the world and with the state of the economy, we can’t reach an agreement to avoid a government shutdown, because the bottom line is we’re working off the same number,” he said in a statement. The challenge now is to identify cuts that will not “eviscerate the ability of the economy to grow,” he added.

House Republican leaders initially proposed $32 billion in cuts for FY 2011, but yielded to conservative pressure to increase proposed cuts to $62 billion. Reverting to the lower level will be a tough sell for many House conservatives.

“We made a promise of $100 billion in our Pledge to America, and it’s going to be difficult to come off that,” says freshman Rep. Blake Farenthold (R) of Texas, who won a tough election with tea party support. Commenting on today’s tea party rally, he added: “I think they need to be here – [to] have our backs.”

For weeks, Senate Democratic leaders have called on Speaker John Boehner (R) of Ohio to break with the tea party wing of the Republican Party in these budget negotiations or risk a shutdown.

“Let me reiterate my hope that the Republican leadership recognizes that they can't continue to be pulled to the right by a radical, unrealistic, unreasonable and unpopular faction,” said Senator Reid in a floor speech on Wednesday. “If they want to move the country forward, they can't let the tea party call the shots.”

A new CNN/Opinion Research Corporation poll, released Wednesday, signals that public support for the tea party movement is slipping. Only 32 percent have a favorable opinion of the movement, down from 37 percent in December. At the same time, 47 percent of Americans now view the tea party movement unfavorably. That compares with 48 percent who view the Republican and Democratic parties unfavorably. (The margin of error is plus or minus 3 percentage points.)

But the tea party is still a powerful presence on Capitol Hill, especially within the House Republican conference. While only 57 of 241 Republicans formally joined the House Tea Party Caucus, most conservatives share the movement’s focus on cutting spending and reining in the size of government. Moreover, Republicans, including tea party Republicans, are wary that appearing to cave to Democrats on spending could leave them vulnerable to primary challenges from the right in 2012.

“Democrats know that if main street Republicans and tea party Republicans split, it’s all over,” says 10-term Rep. Jack Kingston (R) of Georgia.

In a nod to today’s rally, Senate Republicans Thursday afternoon will launch a “consensus balanced budget amendment to the Constitution,” a move they say will “dramatically cut the nation’s $14 trillion debt.”