Grassley wrote to Holder on Monday asking him to clarify how Justice will cope with the sequester, which will mean a $1.6 billion reduction in spending once it takes effect on Friday. Grassley asked a series of questions, including whether it makes sense to reduce the use of these jets in order to help maintain funding in other areas.

"What impact, if any, will sequester have on executive travel via executive jets operated by the Department?" he asked. "Given the OMB Memo recommendation to 'use any available flexibility to reduce operational risks and minimize impacts on the agency's core mission,' will the Department eliminate or significantly curtail non-mission travel on executive jets operated by the Department?"

Grassley said $11.4 million was spent from 2007 to 2011 for 697 "non-mission" travel by senior Justice Department officials.

More broadly, Grassley accused Holder of pursuing a "sky is falling" approach to the required cuts, and said Justice should offer more assurances to the public that key functions of the department will continue.

In a February letter, Holder outlined cuts of $550 million to the FBI, $60 million to the U.S. Marshals Service, and $100 million to the U.S. Attorneys, among others. But Grassley said Holder did not say whether the National Security Division, Criminal Division and Civil Rights Division would be cut by the sequester.

He also questioned whether Justice should continue to plan to spend $165 million for a prison facility in Illinois when the Bureau of Prisons is facing a $338 million cut due to the sequester.