WASHINGTON (CN) — Concerned the White House will shake off terms of oversight laid out for a $500 billion chunk of the $2 trillion coronavirus relief package, in a letter issued Tuesday, a trio of Democratic Senators urged Treasury Secretary Steve Mnuchin to hold up his end of the hard-fought bargain.

The ink was barely dry on the historic Coronavirus Aid, Relief, and Economic Security Act, or CARES Act, this past Friday when President Donald Trump issued something known as a signing statement that immediately challenged terms of the bill only freshly turned into law.

Treasury Secretary Steven Mnuchin speaks during a March 17 press briefing with the coronavirus task force, as President Donald Trump looks on. (AP Photo/Evan Vucci)

Specifically, Trump noted the relief package contained provisions that “raised constitutional concerns,” like its requirement that the newly created Special Inspector General for Pandemic Recovery be subject to oversight requirements like notifying Congress immediately if the executive branch withholds information requested by investigators.

In Tuesday’s letter, Senate Minority Leader Chuck Schumer, D-N.Y., along with Democratic Senators Sherrod Brown of Ohio and Ron Wyden of Oregon, urged Mnuchin to act with haste, encourage the president to appoint the special inspector general soon and begin the next steps of oversight as $500 billion in relief money for businesses and industry begins flowing from the federal coffers.

“Given the substantial amount of taxpayer funds provided to address the economic impact of the coronavirus and the considerable discretion you asked for, Congress took special care in creating the [Special Inspector General for Pandemic Response],” the senators wrote.

Special inspectors were appointed following the 2008 recession and independent auditors were also appointed to oversee U.S. reconstruction efforts in Iraq and Afghanistan. The very beginnings of oversight, at the very least, will be enforced here too, the lawmakers said.

“Each of these positions has operated expressly within the clear dictates of their statutory mandate. We expect the Special Inspector General of Pandemic Response to be granted the same opportunity to have unfettered ability to execute its duties as laid out in the CARES Act,” Schumer, Wyden and Brown wrote. “The administration, including the Department of the Treasury, must be accountable to taxpayers.”

The Treasury Department did not immediately return request for comment.