The “impediment” you speak of is the state of mortal sin. One cannot enter the Church, let alone receive the Eucharist, if he plans to continue living in such a state. Rather, he should cease living as a married person (e.g., live as brother and sister instead) until the marriage issue is resolved. That way he can enter the Church in the state of grace and fully live the sacramental life.
Contact your local pastor or RCIA director for more information.
