Need a quick three billion dollars, Uncle Sam? How about looking in your own pockets?

Deficit cutters struggling to make ends meet in Washington are eyeballing an unusual pot of potential revenue: back taxes owed to the government by federal employees themselves.

According to an IRS study last year, those employees and federal retirees owed a staggering $3.3 billion dollars in delinquent tax payments to the government.

The federal agency with the largest back-tax bill? The US Postal Service, where hundreds of thousands of employees owed a total of more than $283 million, said the report.

Also high on the list is the Department of Veterans Affairs, where employees had more than $156 million in back taxes.

The biggest group, though, is retired military personnel. That group owed more than $1.5 billion dollars.

And even the White House folks are behind in their taxes. Employees in the executive office of the president, which includes nearly 2,000 employees, owed more than $831,000 to Uncle Sam, the IRS found.

The large agency with the highest delinquency rate per employee was the Federal Mine Safety and Health Review Commission, where more than 11 percent of employees owed back taxes, followed by the Government Printing Office, where nearly seven percent were in arrears.

But collecting on all that money isn't easy—federal employees are entitled to the same rights as everybody else. The federal government can't simply dock their paychecks for the delinquent money.

Federal employees “are entitled to the same process under the tax law as you are,” said IRS spokesman Anthony Burke. “They don’t have different rights than everyone else.” Burke said that each taxpayer likely will receive three or four notices about the back taxes before the IRS can take more serious action.

And the IRS spokesman said much of this money could well be paid back in time as the delinquencies work their way through the system.

CNBC