The U.S. House of Representatives on Wednesday passed by 39 votes a measure that bars treasury and securities regulators from spending money to penalize financial institutions that work with legal marijuana businesses.

But they did so without exactly saying banks could openly, and without worry, work with the industry — what banks have asked for in writing — and without decriminalizing the drug at the federal level.

In a separate vote, the House rejected a measure that would have blocked federal guidance given to banks in February for how to work with the marijuana industry — a road map that’s all but frozen financial institutions from providing the services because it lacks guarantees against being penalized.

The amendment the House approved to appropriations bill House Resolution 5016 — co-sponsored by Rep. Ed Perlmutter, D-Lakewood, and three other representatives — takes aim at the Department of the Treasury’s oversight of banks by narrowing the scope of earlier directives the agency gave for banking with the marijuana trade.

It was approved 231-192. The defeated amendment, proposed by Louisiana Republican Rep. John Fleming Jr., lost 236-186.

With Rep. Denny Heck, D-Wash., offering the amendment, Perlmutter’s co-sponsors included Rep. Barbara Lee, D-Calif., and Rep. Dana Rohrabacher, R-Calif.

Perlmutter called the appropriations-bill amendment “a positive step forward for financial institutions and for legitimate marijuana businesses.”

“It is not fair to small businesses and employees in Colorado, and in the 33 other states and District of Columbia, where some form of marijuana is legal or decriminalized, to be forced out of the banking system and discriminated against by the federal government,” Perlmutter said in a statement.

Industry proponents hailed the measures as groundbreaking, while bankers offered a more conservative opinion.

“This is a huge step forward for the legal cannabis industry,” said Aaron Smith, executive director of the National Cannabis Industry Association. “Access to basic banking services is one of the most critical challenges facing legal cannabis businesses and the state agencies tasked with regulating them.”

Although representatives back the measure, approval in the Senate — where the bills head next — is far from certain, bankers say.

“If this provision eventually becomes law — and one vote is far from that — an initial reading is that this appears to remove some of the barriers for the (Office of the Comptroller of the Currency) to financial services being available to marijuana businesses,” said Don Childears, president and CEO of the Colorado Bankers Association. “It is not clear if this applies to the Federal Reserve or the FDIC. Questions still outnumber firm answers.”

The move comes on the heels of another bill, HR 5106, which passed in May. It restricts the U.S. Department of Justice and the Drug Enforcement Administration from meddling with state-approved medical marijuana programs.

Both measures are headed to the Senate. It is unclear when they will be taken up.

“If implemented, this amendment will help alter the current untenable status quo that forces otherwise law-abiding businesses to operate on a cash-only basis, making them a target for criminal actions and unduly burdening their operations,” said Erik Altieri, communication director for NORML, a national advocacy group to legalize marijuana.

Although the measure doesn’t specifically say banks can deal with marijuana businesses with impunity — they still must follow strict banking laws requiring due diligence in dealing with customers and ensuring a proactive anti-money-laundering program — advocates say it helps.

“It’s essentially forbidding the use of funds to target these banks,” said Taylor West, deputy director of NCIA. “Given that many banks seemed to feel that the guidance issued in February was not concrete enough to give them the confidence to start taking cannabis-related clients, it would be a big deal to put that policy into actual law.”

Two U.S. senators — Dianne Feinstein, D-Calif., and Charles Grassley, R-Iowa — have challenged the treasury department’s guidance rules, issued by its Financial Crimes Enforcement Network branch, saying they usurped federal laws that still hold marijuana illegal.

Colorado’s Marijuana Industry Group said the lack of banking services can be solved only at the federal level.

“State-licensed cannabis businesses would like to pay their federal income taxes with a check instead of cash,” MIG executive director Michael Elliott said in a statement.

The Denver Post wrote of an Internal Revenue Service practice of charging a 10-percent penalty to businesses that pay employee withholding taxes in cash rather than electronically. Marijuana businesses without bank accounts suffer disproportionately because they have no choice but to pay in cash, according to a challenge in U.S. Tax Court.

The story prompted Perlmutter and U.S. Sen. Michael Bennet to urge the IRS to temporarily suspend the penalty until the marijuana-banking issue can be resolved.

Wednesday’s action in Congress, however, would not directly impact how the IRS regulation is applied.

Colorado and Washington are the only two states where recreational marijuana sales are legal. Voters in Alaska and Oregon are set to take up the issue in November elections.

Twenty-three states, including Colorado, and the District of Columbia have legalized medical marijuana.

David Migoya: 303-954-1506, dmigoya@denverpost.com or twitter.com/davidmigoya