The state Cannabis Control Commission plans to forge ahead in developing a legal marijuana market in Massachusetts, despite uncertainty generated Thursday by U.S. Attorney General Jeff Sessions' rescission of an Obama-era policy that directed federal law enforcement to adopt a laissez faire stance in states that have legalized marijuana.

Sessions' decision has the potential to threaten the growing legal pot industry that voters and lawmakers in Massachusetts have begun to put in place.

The attorney general, who has long resisted the softening societal views of marijuana, announced in a memo Thursday to prosecutors that he has rescinded the so-called Cole Memorandum. The Department of Justice referred to Sessions' decision as "a return to the rule of law."

"It is the mission of the Department of Justice to enforce the laws of the United States, and the previous issuance of guidance undermines the rule of law and the ability of our local, state, tribal, and federal law enforcement partners to carry out this mission," Sessions said in a statement. "Therefore, today's memo on federal marijuana enforcement simply directs all U.S. Attorneys to use previously established prosecutorial principles that provide them all the necessary tools to disrupt criminal organizations, tackle the growing drug crisis, and thwart violent crime across our country."

Gov. Charlie Baker's office called Sessions' rescission of the Cole Memorandum "the wrong decision" and said the Republicans will continue to support the CCC's work.

"The Baker-Polito Administration fully supports the will of the voters and the CCC's mission," a spokesman said in a statement. "The administration believes this is the wrong decision and will review any potential impacts from any policy changes by the local U.S. Attorney's Office."

State Attorney General Maura Healey, a Democrat, also blasted the decision, saying in a statement that the announcement "inexplicably directs federal law enforcement resources away from combatting an opioid epidemic that is ravaging our communities in order to focus on legalized marijuana." She added that her "office is committed to assisting the [CCC], local municipalities and our partners in law enforcement to implement the will of the voters effectively."

The Cole Memorandum, written in 2013 by then-Deputy Attorney General James Cole, provided guidance to federal law enforcement instructing them to not interfere with legal and regulated marijuana markets established by individual states.

In a statement, the CCC did not speculate as to what Sessions' actions might mean for the industry here but pledged to forge ahead.

"The role of the Cannabis Control Commission remains the same — to fulfill the will of the voters of Massachusetts by implementing and administering a regulatory process that is safe, equitable and efficient," the CCC said in a statement. "Our priority has always been to protect public safety and develop regulations that are compliant with all laws including those passed by the voters and the legislature legalizing the recreational use of marijuana in the Commonwealth."

The agency, which late last month filed its draft regulations for the legal pot industry, added, "As far as the mandate and the work of the Cannabis Control Commission is concerned, nothing has changed. We will continue to move forward with our process to establish and implement sensible regulations for this emerging industry in Massachusetts."

The rationale of the Cole Memorandum was that robust state regulation of legal marijuana businesses could accomplish federal priorities of preventing the drug from falling into the hands of minors, cutting off funding to drug gangs and reducing gun violence — without the need for additional federal enforcement.

That policy gave states the ability to legalize marijuana without much fear of a crackdown from the federal government, which still considers marijuana among the most dangerous drugs under federal law.

Voters in Massachusetts legalized marijuana in 2016 with about 54 percent of voters supporting the measure and state regulators are working towards an expected July 1 start of retail sales. The CCC filed 107 pages of draft regulations for the marijuana industry with the secretary of state's office and is planning to hold a series of public hearings in February to gather feedback on the proposed rules.

"It is distressing to see Jeff Sessions making such a regressive move at a time when more and more states — and countries such as Canada — are replacing failed cannabis prohibition policies with smart, regulated approaches," Jim Borghesani, spokesman for the local chapter of the Marijuana Policy Project, said in a statement Thursday. "However, the true test will be how individual U.S. attorneys move forward in a post-Cole Memorandum environment. My hope is that they recognize and respect decisions by voters in legal states."

With Sessions leaving decisions related to enforcement of federal marijuana laws in states that have legalized the drug up to individual US attorneys, it will be up to Massachusetts' newly minted U.S. attorney, Andrew Lelling, whether to crack down on the state's legal and regulated cannabis system.

In a statement given to WBUR Thursday evening, Lelling said:

As with all of our decisions, we will continue to use our prosecutorial discretion and work with our law enforcement partners to determine resource availability, weigh the seriousness of the crime and determine the impact on the community. In the spirit of the Attorney General’s memo, I intend to meet with our federal partners to discuss enforcement efforts and priorities. In the coming weeks I also plan to meet with our local and state counterparts to reinforce our commitment to assisting local communities in this effort. As the Justice Department has highlighted, medical studies confirm that marijuana is in fact a dangerous drug, and it is illegal under federal law. As a result, our office will aggressively investigate and prosecute bulk cultivation and trafficking cases, and those who use the federal banking system illegally.

U.S. Sen. Cory Gardner, a Republican from the legal weed state of Colorado, blasted Sessions' decision on Twitter on Thursday morning and said he is willing to hold up presidential nominations to the Department of Justice if Sessions follows through.

"This reported action directly contradicts what Attorney General Sessions told me prior to his confirmation," Gardner tweeted. "With no prior notice to Congress, the Justice Department has trampled on the will of the voters in CO and other states."