In a dramatic House vote, 54 Republicans broke ranks with their own leadership Tuesday to oppose a three-week stopgap measure to keep government funded beyond March 18, when the current continuing resolution expires.

The spending bill, which passed 271 to 178, cuts $6 billion from fiscal year 2010 spending levels. It now heads to the Senate, where the Democratic majority leader promises action this week.

The rift in Republican ranks caps a week of high frustration in which neither the Senate nor the White House brought a plan to the table that makes a dent in a projected $1.65 trillion deficit for the 2011 fiscal year, which ends Oct. 1. Conservatives, including many in the 87-member GOP freshman class, say the time for a showdown with Democrats – and with their own leadership – over the need for significant budget cuts is now.

“We’re spending $45 billion a day, what’s $6 billion in cuts?” says freshman Rep. Allen West (R) of Florida, who voted to oppose the bill. “I voted for the last CR – that’s it for me.”

Bowing to conservative pressure, especially from the GOP freshmen, House Republicans in February passed a spending bill to fund government through the end of FY 2011 that cut $62 billion from 2010 spending levels. In response, last week, the Senate took back-to-back votes on the House bill and an alternative proposed by the Senate Appropriations panel that cut only $6 billion, mainly comprising programs that were already slated to be scrapped by President Obama. Both measures failed, forcing House Republicans to scramble for another short-term fix.

The latest House continuing resolution cuts or eliminates 25 programs, many already identified for elimination by the White House in its budget for FY 2012. In addition to $3.5 billion in program cuts, the House plan also zeros out $2.6 billion for member projects or earmarks. It cuts in three weeks what Senate Democrats proposed cutting over six months. The current two-week continuing resolution cut $4 billion from 2010 levels.

“Enactment of this short-term measure would mean $10 billion in cuts in just five weeks, which is $10 billion more than the Democrats who run Washington originally suggested,” said Speaker John Boehner (R) of Ohio, in a statement after the vote. “But if we’re serious about ending uncertainty for small businesses and helping them get back to creating jobs, we need to cut a lot more.”

But from now on out, lawmakers on both sides of the aisle say that those cuts get harder. Democrats predict that Tuesday’s vote will mark high-water mark for the new majority. “This would not have passed if Democrats had not helped,” said Rep. Steny Hoyer (D) of Maryland, the minority whip, after the Tuesday vote. Eighty-five Democrats voted with most Republicans to pass the bill. With GOP votes alone, Republicans would have fallen 32 votes short of a majority.

The rift signaled in Tuesday’s vote could give Democrats an edge in negotiations with the GOP majority that they did not have before by presenting themselves as more agreeable partners on future spending bills.

“They had 54 people that couldn’t vote for this bill – that number only grows,” says Rep. Robert Andrews (D) of New Jersey, a member of the House Budget Committee. A top priority of Democrats will be to protect education spending, he adds. “Anything to do with the repeal of health care or funding of Planned Parenthood also can’t be part of the deal,” he added.

On the other hand, House GOP leaders could opt to shift toward their tea party freshmen, and try to muscle a bill through on the strength of their own majority – risking a government shutdown.

"In the short run, maybe Democrats can get away without putting anything on the table," says Michael Franc, vice president for government affairs at the Heritage Foundation, a conservative think tank. "But if this is the high-water mark for spending cuts in a $1.6 trillion deficit environment, that should be a clarion call for 2012."