A group of the most fervent budget hawks in Congress have found at least one spending cut that they don’t like: proposed cuts the Government Accountability Office’s budget.

Claiming that the proposed 7 percent cut will be “overly burdensome” to the government watchdog agency, five senators, including four Republicans and one Democrat, sent a letter to the appropriators today in protest.

“We are, however, concerned that the Government Accountability Office (GAO) is being unfairly singled out with both excessively deep cuts and overly burdensome new mandates that will consume the agency’s more limited resources for no apparent benefit.”

The letter is signed by Senators Tom Coburn, R-Okla., John McCain, R-Ariz., Scott Brown, R-Mass., Ron Johnson, R-Wisc., and Claire McCaskill, D-Mo.

This month The Senate Appropriations Committee approved Chairman Ben Nelson’s, D-Neb., plan, within the fiscal year 2012 Legislative Branch appropriations bill, to cut Congress’ spending by 5.2 percent, amounting to a $200 million saving.

“These cuts are strategic and sensible. But make no mistake, they are real and will force Congress and the agencies on Capitol Hill to live with less,” Nelson said of the proposed cuts in earlier this month, “As Congress works to bring down federal spending, bring down the debt and balance the federal budget, Congress must tighten its own belt.”

The proposal calls for a 7.6 percent cut to the GAO, the independent, nonpartisan agency that served as a congressional watchdog investigating how the federal government spends taxpayer’s money.

“While we agree GAO must face the same harsh fiscal realities being applied to every other federal agency and program, the cut to the agency’s budget represents more than 10 percent of the entire reduction proposed within legislative branch spending,” the bipartisan group of senators write in the letter to Chairman Nelson and Ranking Member Hoeven on the Senate Appropriations Committee. “There is no question oversight of the federal government, a primary function of the legislative branch, will suffer as a result of this dramatic cut to GAO funding.”

In an op-ed in The Washington Examiner this morning Sen. Coburn dubs this the “Senate appropriators’ secret war against oversight.”

“The logic of the committee’s proposal is tough to decipher,” Coburn writes, “At a time when we are running a $15 trillion debt and are borrowing $4.5 billion a day to keep government open and our military deployed, every agency needs to tighten its belt. Yet, the Appropriations Committee proposal looks like mismanagement at best and pay back at worse.”

Another bipartisan letter was sent to the Committee on Homeland Security and Governmental Affairs, echoing the same concerns by Senator Lieberman, I-Conn., and Susan Collins, R-Maine.

“GAO’s role in identifying inefficient and ineffective use of government funds and illegal or improper activities is critical to ensuring that taxpayer funding is wisely and appropriately spent,” Lieberman and Collins write.

Nelson’s office did not have a specific reaction to the letters today, only to echo the statement the Senator made earlier in the month about the need for Congress to tighten its belt. The senators have requested that the bill be updated before it comes to the Senate floor.