Washington (CNN)- House Republican leaders, already facing GOP defections over a spending bill many think doesn't cut enough, are now scrambling to stem Republican concern that what it does cut is only a fraction of what's being advertised.
At issue is a new report from the Congressional Budget Office that says while the spending bill does cut roughly $38 billion, only a small part of that – $352 million – will be realized this year.
The discrepancy centers around the arcane difference between what's known as budget outlays, how quickly money is spent, and budget authority, how much agencies are allowed to spend on a given program.
House Speaker John Boehner admitted this has "caused some confusion" among rank and file Republicans.
He even went to the floor of the House with charts and graphs.
"There are some who claim that the spending cuts in this bill aren't real, that they are gimmicks. Well, I just think it is total nonsense. A cut is a cut," he said.
CNN is told by multiple GOP leadership sources that they are scrambling behind the scenes to try to reassure Republican lawmakers the cuts are real, so that they don't lose even more votes than they had already anticipated.
House Majority Whip Kevin McCarthy sent out a fact sheet Wednesday night, and arranged an emergency meeting for House GOP lawmakers Thursday morning with former CBO director Doug Holtz-Eakin to try to calm concerns they are voting for what some worry are spending cuts that are smoke and mirrors.
CNN is told by two GOP sources that meeting got intense, as GOP lawmakers expressed skepticism about the spending cuts the Speaker negotiated with Democrats.
House Majority Leader Eric Cantor told CNN they are "making sure" that the message is getting out that they believe these are real spending cuts.
"I would just say this, the budget process as you know is very arcane. You have outlay issues and you have budget authority issues. The bottom line is we're cutting spending here. There's $38 billon in budgetary authority that is reduced off of the current fiscal year," said Cantor as he walked into the Speaker's office.
Freshman Republican Joe Walsh, R-Illinois, is still not convinced, even after reviewing Holtz-Eakin's analysis Wednesday night and talking to him by phone.
"It certainly doesn't help the case," said Walsh, who added that this has been subject of multiple internal meetings since Wednesday night.
Rep Jack Kingston, R-Georgia, also said the CBO report is causing confusion, but also cautioned that Republican leaders shouldn't "oversell" what the budget deal does in terms of cutting spending and need to talk about the bigger efforts he says House Republicans are moving on to make next.
"This is a good day's work but it's not the year's work," Kingston said.
Kingston said Republican defections on the budget vote won't have any long term impact on Speaker Boehner keeping the GOP conference together because the party is united on the bigger budget battles ahead.
"I think he's going to be fine because the big policy changes are in the Ryan budget and not in the CR cuts. And then since the Democrats are attacking Ryan led by the President of the United States that's going to reunify us and regain whatever ground any inside the family leadership might need."