BOSTON (AP) _ A group that spearheaded legalization of recreational marijuana in Massachusetts is calling Attorney General Jeff Sessions' decision to rescind a federal policy on legal pot ``distressing'' and a ``regressive move.''

Two people with knowledge of the decision told The Associated Press that Sessions planned to announce Thursday he was rescinding an Obama-era policy that allowed legal marijuana to flourish in states that permit it, and will instead allow U.S. attorneys to decide how aggressively to enforce federal marijuana laws in those states.

Massachusetts voters approved a 2016 ballot question legalizing recreational marijuana. The state's first pot shops are expected to open later this year.

Jim Borghesani, a spokesman for the group that led the ballot initiative, called on federal prosecutors to ``recognize and respect decisions by voters in legal states.''