Speaker John Boehner (R-Ohio) is facing pressure from his right to follow through with $100 billion in cuts to the budget this year.

A key member of the conservative Republican Study Committee (RSC) publicly wrote Boehner on Monday, urging him to pursue the $100 billion in cuts that the GOP had promised in its "Pledge to America," the pre-election agenda document the party released last fall.

"With this historic opportunity to cut spending and grow our economy, it is critical that our conference, at a minimum, meet the original $100 billion savings goal through the [continuing resolution]," wrote Rep. Scott Garrett (R-N.J.) to Boehner in a letter released this afternoon.

Garrett, the head of the RSC's Budget and Spending Task Force, sought to pressure Boehner into following-through with the "Pledge" as the party has backed off, to an extent, the $100 billion figure.

"We believe the first step in restoring the trust of the American people and rebuilding the American economy is, simply, to do what we said we would do during the campaign.  Our first opportunity to do so will be upon us shortly," Garrett wrote.

At issue is the way the continuing resolution (CR) that currently funds the government is structured. Lawmakers authorized a CR that funds the government, at 2010 levels, through March of this year, by which time half of the U.S. government's fiscal year will have passed. Because of this, Republicans say it's only reasonable to expect $50 billion in cuts through their stated goal of reducing spending to 2008 levels.

Conservatives have proposed much more audacious initiatives to curb spending, however. Rep. Jim Jordan (R-Ohio), the chairman of the RSC, last week proposed an agenda outlining $2.5 trillion in cuts over the next decade -- a proposal that Majority Leader Eric Cantor (R-Va.) hailed. The RSC had also claimed that the rules crafted by new Republican leaders were too friendly to spending-friendly appropriators in the House.

Garrett's letter underscores the occasional tension Boehner and other top Republicans will encounter with more conservative members of their conference, many of which were elected in 2010, and boast ties to the activist Tea Party movement, which is on the lookout for apostasy by Republican leaders in Congress.