A federal judge won't allow a family of a medical marijuana patients from Washington state to defend themselves against drug trafficking charges by arguing their pot plants were for medical purposes.

U.S. District Judge Fred Van Sickle of the Eastern District of Washington on Tuesday rejected the planned medical marijuana defense of Larry Harvey, 70, his wife Rhonda Firestack-Harvey, 55, and three others facing trial next week, saying they could not argue that growing marijuana was for medical purposes and legal under Washington state law.

"The intent of the defendants is not relevant to the issues," Van Sickle said. "There's this concept of reliance on state law and the like. That's not relevant either."

Because the federal government considers marijuana illegal, federal courts generally don't allow evidence that the drug may have been used for medical purposes, even when medical marijuana is legal under a state's law, as it is in Washington. The Harveys, their son, Rolland Gregg, 33; Gregg's wife Michelle, 35; and family friend Jason Zucker, 38, sought to describe their doctor-recommended medical marijuana cultivation at their upcoming trial on federal drug charges.

"You can tell a portion of the truth, just a bit of the truth and only the truth they want you to tell," said Kari Boiter, the Washington state coordinator for the medical marijuana advocacy group Americans for Safe Access, who accompanied Larry Harvey at Tuesday's hearing. "Forget 'the truth, the whole truth, and nothing but the truth,'" Boiter added.

The group claims they were growing 74 medical marijuana plants for their personal use at the Harveys' rural home near Kettle Falls, Washington. Defense attorneys said the pot patch complied with state law.

Nevertheless, the federal government has charged each with six felonies, including manufacturing, possession and distribution of marijuana, as well as possessing a firearm in furtherance of drug trafficking.

The family kept numerous firearms at the home, in the wilderness of northeast Washington state, near the U.S.-Canadian border, for hunting and defense, their lawyers said. They have encountered black bears, cougars and coyotes at their front door on several occasions, according to the lawyers.

"It doesn't matter that we used the shotgun to hunt turkeys and the hunting rifle for deer," Rhonda Harvey said in a statement to the media last week.

Federal prosecutors say the presence of firearms shows the defendants were involved in drug trafficking.

Defense attorneys argue that the defendants were not "perceived to be violent in any way" and that the guns had nothing to do with the cultivation of medical cannabis.

The home was raided by state authorities on Aug. 9, 2012, according to court documents. State law enforcers found 74 plants growing near the home. Under the presumption that the family was growing this cannabis as a collective, rather than individually, officers seized 29 cannabis plants so that the family would be compliant with state law, which limits collective crops to no more than 45 plants. State authorities did not press charges or seize anything else.

A week later, federal authorities conducted a more comprehensive raid, seizing the Harveys' remaining marijuana plants, as well as about five pounds of raw cannabis and some marijuana-infused edibles from the freezer. The feds also seized a 2007 sedan, several hundred dollars, firearms and some personal belongings.

"This is not the kind of spectacular haul that the DEA is typically called in for," the family's attorneys wrote in a letter to Attorney General Eric Holder in February, urging him to reconsider the charges. "Just the opposite, the evidence seized is consistent with the type of strict medical dosage that occurs with a doctor's supervision."

Washington legalized medical marijuana in 1998 and recreational marijuana in 2012. Still, federal law classifies marijuana a Schedule I substance "with no currently accepted medical use."

Michael Ormsby, the U.S. attorney for the region, filed a court motion last week requesting "any evidence of medical purposes as well as the defendants' belief that they were lawfully engaged in marijuana cultivation" be inadmissible at trial. Ormsby argued that the family's purpose for growing marijuana is not the issue. Rather, he said, the "knowing or intentional manufacturing of marijuana" is what matters.

Defense attorneys argue that there is an "equal justice disparity" created by federal drug laws that contradict state laws.

"Here you have a single family facing a combined 60 years in mandatory minimum sentences for medical marijuana in the same state that plans to allow cannabis distribution on a scale unlike anyone has seen before," the defense attorneys wrote to Holder.

In August, Deputy Attorney General James Cole issued guidelines for all U.S. attorneys, saying it's "not an efficient use of federal resources to focus [medical marijuana] enforcement efforts on seriously ill individuals." Cole's memo also outlined what the federal government still regards as prosecution priorities, including "preventing violence and the use of firearms in the cultivation and distribution of marijuana."

Larry Harvey, a recently retired commercial truck driver of 30 years, ate marijuana-infused cookies to ease symptoms related to gout, chronic pain and inflammation, according to his attorneys. Rhonda Harvey suffers from osteoarthritis and has undergone joint and bone surgeries. Medical cannabis eased her inflammation and pain, the lawyers said. Rolland Gregg and Zucker used medical marijuana to treat back injuries. Michelle Gregg used cannabis for appetite stimulation due to wasting brought on by a medical condition she hasn't disclosed.

In March, Holder announced support for sentencing reform that would reduce prison time for some nonviolent drug crimes. Last week, a White House official told Yahoo News that President Barack Obama may grant clemency to "hundreds and perhaps thousands" of people who have been jailed for nonviolent offenses.

Harvey family lawyers argue that the defendants were "clearly abiding by the rest of the priorities laid out in the latest Cole memo" and the U.S. attorney should therefore drop the charges.