Marxist Working Group (in Swedish: Marxistisk Arbetsgrupp) was a left communist group in Sweden. The group emerged from a split in the VPK branch of Birka-Vasa in 1974. Since the late 1960s a section of the Birka-Vasa branch had developed left communist leanings. By 1974 they broke away, and the majority of them joined MA. Many had been part of the branch board of VPK Birka-Vasa 1969-1974. MA existed parallel to (Förbundet Arbetarmakt), another left communist group in Sweden at the time.