A powerful U.S. House panel that oversees federal drug enforcement efforts approved a bill on Thursday to require the Department of Justice and Attorney General Jeff Sessions to begin issuing more licenses to grow marijuana for research.

Prior to the vote, a bitter dispute broke out over a provision of the legislation that prevents anyone with a “conviction for a felony or drug-related misdemeanor” from being affiliated with cannabis research cultivation operations.

“There is no legitimate health or public safety justification for the inclusion of this language and we urge you to strike this unnecessary, punitive ban on individuals with previous drug law violations,” reads a letter sent to the committee's leaders on Wednesday by the American Civil Liberties Union, Human Rights Watch, #cut50, the Drug Policy Alliance and other groups. “To help lower recidivism rates and improve public safety, we should be making it easier for people with records to obtain jobs, not more difficult.”

Legalization supporters scrambled this week to build support to amend the bill accordingly, but House Judiciary Committee Chairman Bob Goodlatte (R-VA)—who has long opposed marijuana reform but is a cosponsor of the research legislation—refused to go along with a compromise that would have stripped the restrictions on people with drug misdemeanors while maintaining the ban on those with felony convictions, Capitol Hill staffers and advocates said.

As a result, some drug policy reformers who otherwise strongly support expanding marijuana research balked on the bill, urging lawmakers to vote no.

The legislation as introduced "unfortunately and unjustly expands the collateral consequences of criminal convictions," Rep. Jerrold Nadler (D-NY), the top Democrat on the panel, said at the start of an hour-long debate before the vote.

Citing the racially disproportionate manner in which drug laws have been enforced, he said the restrictions in the bill would "compound this injustice by preventing the very people who have been harmed from participating" in research.

But Goodlatte argued that it is "wholly appropriate that we set a firm standard for those who are supposed to be growing and manufacturing research-grade marijuana."

During the committee markup, Rep. Steve Cohen (D-TN) offered an amendment to remove the words "drug-related misdemeanor” from the provision in question, but ultimately withdrew the proposal instead of forcing a vote after Goodlatte made a commitment to work to revise the restrictions before the bill goes to the House floor. The chairman indicated that he would "probably not object" to a carve-out for people with drug possession convictions.

The overall bill, the Medical Cannabis Research Act, sponsored by Rep. Matt Gaetz (R-FL), was then approved by a voice vote.

“While there are many varying opinions on the issue of marijuana, one thing we all can agree on is that we need qualified researchers to study the science to determine if there are any potential medicinal benefits to chemicals derived from cannabis," Goodlatte said in a statement.

@RepMattGaetz - "We must ensure that an adequate and uninterrupted supply of research-grade cannabis is available to safe harbor provisions for research facilities. I am proud to lead the efforts to unlock cures through important scientific research."

Earlier in the week Gaetz tweeted that “both sides make fair points” about the drug conviction language, but the issue “isn’t important” to him.

“What a shame if disagreement on such a small thing kept us from making University/Hospital/Hospice/VA/MedSchool #MedicalMarijuana research collaboration legal with the vibrant, innovative commercial cannabis industry,” he wrote.

@mattgaetz- "This isn’t important 2 me. Both sides make fair points. But what a shame if disagreement on such a small thing kept us from making University/Hospital/Hospice/VA/MedSchool #MedicalMarijuana research collaboration legal with the vibrant, innovative commercial cannabis industry."

@tomangell- "Legalization advocates are concerned provisions in this @mattgaetz bill to bar people with drug convictions from legally growing marijuana for research, but he told me in an interview it was a necessary compromise to get GOP votes this week.https://www.forbes.com/sites/tomangell/2018/09/10/marijuana-bill-scheduled-for-congressional-vote-this-week/ …"

During the committee hearing on Thursday, Gaetz said that the restriction wasn't included in initial drafts of the bill and its addition was suggested by people in the marijuana industry who "wanted to raise the bar" and not have "people who wandered out of their drug circle or hacky sack endeavor" leading cannabis research.

Morgan Fox, communications director for the National Cannabis Industry Association, said in a text message that his organization "absolutely did not suggest that and does not support that restriction."

It is unclear who did suggest it.

While a number of Judiciary Committee Democrats spoke up to say that they could not support the legislation as written, Rep. Ted Lieu (D-CA) said that he was willing to vote to advance it in the hopes of it being amended later.

Rep. Dina Titus (D-NV), who is not a member of the panel, praised its passage in a tweet, as did Rep. Ken Buck (R-CO), who sits on the committee.

@repdinatitus- "Today the Judiciary Committee passed the Medical Cannabis Research Act. This bipartisan bill I've cosponsored is a small step in removing barriers to federal research, including at our VA facilities. There's more work to do, but this is a commonsense bill that should become law."

@RepKenBuck- "Glad to see that HR 5635, The Medical Cannabis Research Act, was adopted by voice in @HouseJudiciary today. This bill wisely regulates medical marijuana research and helps our veterans by allowing the VA to discuss potential medical marijuana trials with them."

Legalization advocates, mindful of growing political momentum for marijuana policy reform, said they have moved past the time when they were willing to make major concessions in order to move incremental legislation.

"While the bill’s consideration represents progress, it’s a drop in the ocean given what we need to do to end federal prohibition and repair the harms of the drug war," Michael Collins of the Drug Policy Alliance said in an interview earlier this week, adding that the restrictive provisions are "egregious, unnecessary and representative of an outdated approach to public policy."

Others cannabis activists cheered the bill's passage but questioned whether more research on marijuana was really needed before Congress moves to change its status under federal law.

“While this vote marks a step forward, it must also be acknowledged that despite existing barriers to research, ample studies already exist to contradict cannabis' federal, schedule I status as a substance without medical utility, lacking acceptable safety, and possessing a high potential of abuse," NORML Deputy Director Paul Armentano said in a press release. "More clinical research is welcome, but unfortunately science has never driven marijuana policy. If it did, the United States would already have a very different policy in place."

@RepMattGaetz- "For too long, Congress has faced a dilemma with cannabis-related legislation: we cannot reform cannabis law without researching its safety, its efficacy, and its medical uses — but we cannot perform this critical research without first reforming cannabis law."

Under current U.S. policy, a University of Mississippi farm has for the past 50 years been the only legal source of marijuana for studies. But researchers have often complained that it is too hard to get approval to use the facility's cannabis products, and that they are often of low quality.

The Drug Enforcement Administration, in the closing months of the Obama presidency, moved to create a process for the federal government to issue additional research cultivation licenses. But the Justice Department under Sessions has blocked the DEA from acting on the more than two dozen applications that have been submitted.

Gaetz's bill, if enacted into law, would force Sessions's hand by requiring the granting of more licenses. It now heads to the House floor.

In addition to the requirement to issue additional cultivation licenses, the bill clarifies that Department of Veterans Affairs (VA) doctors can discuss the medical marijuana with their patients and can refer them to participate in scientific studies on the drug's effects.

The Judiciary Committee vote marks only the second time in history that a congressional panel has approved standalone cannabis reform legislation. Earlier this year, the House Veterans Affairs Committee passed a bill encouraging the VA to conduct research on the medical benefits of marijuana for military veterans.