Sen. Tom Coburn (R., Okla.) is launching an investigation after revelations that sequestration resulted in only one government layoff in 2013.

According to a report released by the Government Accountability Office (GAO), the only layoff that occurred to help achieve the $85.3 billion in spending cuts took place in the Department of Justice (DOJ).

"DOJ officials reported that one DOJ component—the U.S. Parole Commission—implemented a reduction in force of one employee to achieve partial savings required by sequestration in fiscal year 2013," the report said.

Coburn said this fact is "devastating" to the Obama administration and Democratic politicians who issued dire warnings against the automatic cuts. "The pain will be real," Obama said last March.

"Despite relentless warnings about the dire consequences of sequestration’s budget cuts, it appears sequestration resulted in only one layoff," Coburn said in a statement. "While that’s good news for federal employees and other workers, it is devastating to the credibility of Washington politicians and administration officials who spent months—and millions of dollars—engaging in a coordinated multi-agency cabinet-level public relations campaign to scare the American people."

"Taxpayers expect us to root our predictions in fact, not ideology and spin," Coburn added. "The facts seem to say the experts underestimated sequestration’s impact by between 99,999 and 1,599,999 jobs, according to two frequently-cited estimates by Goldman Sachs and the Congressional Budget Office."

The Goldman Sachs study, cited by Coburn, predicted that the budget cuts would cost 100,000 federal jobs.

The GAO report revealed that while many agencies restricted or froze hiring, none except the Parole Commission laid any workers off. Furloughs at agencies were also less severe than predicted in 2013, with the Department of Labor furloughing some employees for only four hours.

The Defense Department was hit the hardest, furloughing 640,500 employees for six days. The Departments of Interior and Treasury furloughed employees for three days, the Environmental Protection Agency (EPA) for six, and the Department of Transportation (DOT) for only one day.

As a result of the report, Coburn sent a letter to the Office of Management and Budget (OMB) Director Sylvia Mathews Burwell on Wednesday, asking for a clearer picture from the administration on sequestration.

"The Budget Control Act is the law of the land until FY 2021, so it is essential to have a complete understanding of how agencies manage their workforces and operations in this constrained fiscal environment," Coburn wrote.

Coburn, who is the ranking member of the Senate Committee on Homeland Security and Governmental Affairs, asked the OMB for the total number of permanent federal civilian employees for the last five years, broken down by agency, position, and pay.

He also asked whether any "legal obstacles" are preventing government agencies from laying workers off to meet budgetary restraints.

The Oklahoma senator also asked for a list of every agency that has "implemented a reduction in force due to sequestration," and any documentation "circulated by OMB advising federal agencies how to manage their federal workforces in response to sequestration."

"The American people deserve to know the truth, especially if it suggests politicians’ favorite programs can endure far more in budget cuts than sequestration imposed," Coburn said.