DENVER — A marijuana banking case set for arguments Monday is testing the federal government’s stated goal of addressing the cash-only nature of the quasi-legal pot industry.

But should pot sellers be able to use the nation’s banking system as long as marijuana is an illegal drug? It’s a question before a federal judge trying to weigh a Colorado-chartered bank’s attempt to force the U.S. Federal Reserve to let those pot shops access the nation’s banking system.

The case involves Fourth Corner Credit Union, which Colorado set up last year to serve the marijuana industry.

Federal banking regulators have issued guidelines for how banks can accept money from pot sales, but banks frequently say those guidelines are unwieldy. That leaves many pot shops stuck trying to pay bills and taxes in cash.

No major marijuana-related cash heists have been reported in Colorado, but the cash-intense nature of the pot industry leaves many in the business feeling nervous about operating in cash. Many Colorado marijuana businesses use armed security.

“The public is at risk in having hundreds of millions of dollars of cash flowing about the streets of Colorado,” the credit union argued in a court filing last summer.

Fourth Corner aimed to solve the dilemma by catering to marijuana-related businesses, filing all the reports federal regulators say should be required of the pot industry. Because marijuana remains illegal under federal law, those who handle proceeds from pot sales could be implicated in a federal racketeering case if they don’t follow the guidelines.

But the U.S Federal Reserve, a private entity that nonetheless acts as the government’s fiscal agent, is standing in Fourth Corner’s way. The Federal Reserve says that despite guidance about pot banking from the Department of Treasury, pot money simply can’t be allowed into the nation’s central banking system as long as the drug remains illegal under federal law.

The credit union “was formed with the intent to serve a federally illegal purpose,” the regional Federal Reserve argued in one of its court filings.

The Federal Reserve also argued that Congress, and not a federal judge, must decide whether pot money can join the nation’s banking system.

“Federal legislators have introduced multiple relevant bills that would address the issues,” the Federal Reserve argues. “The Court should abstain from doing so.”

U.S. District Judge R. Brooke Jackson hears arguments in the case Monday morning. He has no deadline for making a decision.