Democrats on the House Veterans’ Affairs Committee on Thursday implored the committee’s officials to start research on medical marijuana for issues like post-traumatic stress disorder, calling it a potential revolution for veterans’ health.

In a letter signed by every Democratic member of the panel, lawmakers asked VA Secretary David Shulkin to push his department’s Office of Research and Development to “fulfill its stated mission” by looking into the value of cannabis medication as an alternative to addictive prescription opioids.

“VA is uniquely situated to pursue research on the impact of medical marijuana on veterans suffering from chronic pain and PTSD given its access to world-class researchers, the population it serves, and its history of overseeing and producing research resulting in cutting edge medical treatments,” the letter said.

“VA’s pursuit of research into the impact of medical marijuana … is integral to the advancement of health care for veterans and the nation.”

In a statement, committee ranking member Rep. Tim Walz, D-Minn., said the move is overdue.

“Time and time again, I have heard the stories of veterans who have used marijuana medicinally to help them cope with physical and psychological injuries sustained during their service,” he said. “I now know for a fact that research and access to medical marijuana has become a critically important veterans’ issue.”

Cannabis is still illegal under federal law, but 26 states (and the District of Columbia and Puerto Rico) allow access to the drug for medical needs.

At a White House press conference in May, Shulkin said federal law does not prevent his department from looking at marijuana research “as an option for veterans” but not to prescribe the substance.

“My opinion is that some of the states that have put in appropriate controls, there may be some evidence that this is beginning to be helpful,” he said. “And we’re interested in looking at that and learning from that.”

But VA officials have been reluctant to move ahead with assisting in outside research projects in recent months, including an Arizona study lauded by the American Legion, which has repeatedly petitioned local VA facilities to help find participants.

Meanwhile, Department of Justice officials have indicated they do not support loosening rules on marijuana research and have looked into expanded authorities to go after cannabis dealers and companies even in states where the substance is legal.

American Legion officials last year passed a resolution calling for expanded research into medicinal use of marijuana, noting that opioid abuse presents a serious health threat to the veterans community and any alternatives should be considered.

Also on Thursday, Iraq and Afghanistan Veterans of America released a new survey indicating that 63 percent of their members support legalization of the drug for medicinal purposes. Only 15 percent opposed the idea.

One day earlier, a Gallup poll indicated that 64 percent of Americans favor making marijuana legal, the highest figure researchers have recorded in nearly 50 years of polling on the issue.

The Democrats lobbying Shulkin asked for either a public commitment for new studies into the drug or an explanation into “all external and internal barriers to the pursuit of research” by Nov. 14.

In addition, one of the letter signers — Rep. Lou Correa, D-Calif. — introduced a House resolution on Thursday calling for VA to recognize “the urgency and importance of finding alternative successful treatments to opioids” and conduct cannabis research to compare the side effects with current treatment methods.