A key Senate Republican is seeking to block a postal reform bill he argues would require the government to borrow billions more, at a time when the government is already borrowing $1 trillion a year.

Senate Budget Committee ranking member Jeff Sessions (R-Ala.) said the Senate legislation would require the U.S. Treasury to pay back $11.4 billion to the U.S. Postal Service. This is the amount that the USPS overpaid to its own employee retirement system, but Sessions argues that money should still be offset by cutting spending elsewhere.

{mosads}He noted that the $11.4 billion amounts to a little less than $1 billion a year over the next decade, and criticized Democratic leaders for failing to propose a way to find that much in savings.

“We couldn’t find $1 billion a year to pay the money back?” Sessions asked Monday on the Senate floor. “We have to just borrow it in addition to the money we’ve agreed to borrow?”

He also said the bill would allow the govenrment to defer $23 billion in payments that would go toward the USPS’s retiree health benefit plan, an amount he said taxpayers would ultimately have to fund. That’s a total of more than $34 billion taxpayers would likely have to find years down the road in order to implement the bill.

Sessions added that the bill violates language in the Budget Control Act that prohibits committees from reporting bills to the floor that are not paid for.

“This bill does violate that legislation,” he said. “It spends above the agreed-upon limits.”

As a result, Sessions said he would raise a budget point of order to block the Senate bill this week. It would take 60 votes to overturn the point of order, making it more difficult to move the bill forward.

The point of order has the potential to throw off Senate work this week on the 21st Century Postal Service act. Without 60 votes, the bill would be sent back to committee.

Sessions spoke shortly after Sens. Joe Lieberman (I-Conn.) and Susan Collins (R-Maine) defended the bill as a way to give the USPS the authority to take creative new steps to avoid post office closings across the country.

After Sessions spoke, Collins said the Congressional Budget Office’s score of the bill, showing how much it will cost the government to implement, is “incredibly misleading,” and insisted that no taxpayer money would be used to implement the bill. For example, she said the $11.4 billion overpayment comes from money raised only by the USPS, not taxpayers, and thus there would be no real cost to taxpayers.

“These aren’t taxpayer dollars that went into the overpayment in the first place,” she said. Collins added that it only appears to be an $11.4 billion cost when the unified federal budget is looked at, and stressed that the CBO score does not take into account the source of various funds in the unified budget. She said if these factors were considered, the bill would be scored as saving taxpayer money.

“This is so frustrating … because it is so complex,” she said.

Lieberman and Collins argued generally that the bill would let USPS use the $11.4 billion in overpayments to take steps such as right-sizing postal processing plants rather than closing them, and consider steps such as renting out its unused spaces or setting up facilities in retail outlets.

“If we fail to act, if we turn down this bill, the postal service will not survive as we know it today,” she said on the floor.

Lieberman agreed with Collins’s critique of the CBO score.

“This is form over substance,” he said. “This is a kind of ‘Alice in Wonderland’ accounting that doesn’t relate to the reality of the Postal Service.” Earlier, Lieberman cast the bill as the last chance to reach a bipartisan deal to keep the USPS in the black.

“The postmaster has been very clear that if we don’t give him some authority to find a new business model, to economize, that he’ll have to take very, very aggressive action,” Lieberman said.

“This is a moment of truth for the Senate,” he added. “Here’s a great American institution that’s in real fiscal trouble, and we have the ability with this legislation to get it back on a path of balance, stability, and even growth.”

— This story was updated at 2:37 p.m. to reflect Sessions’s argument that the Senate postal bill would cost taxpayers $34 billion, not $11 billion.