סימן צד סעיף כג
יִשְֹרָאֵל מוּמָר אוֹ שֶׁהוּא מְחַלֵּל שַׁבָּת בְּפַרְהֶסְיָא (יֵשׁ אוֹמְרִים, אֲפִלּוּ רַק בְּאִסּוּר דְּרַבָּנָן), הֲרֵי הוּא כְּאֵינוֹ יְהוּדִי וּצְרִיכִין לִשְׂכֹּר מִמֶּנּוּ רְשׁוּת (שפ"ה).
An apostate or a person who publicly desecrates the Shabbos61This applies only when he knows that it is forbidden. If he does not know he probably is not considered an apostate. [Bi’ur Halachah 385: 3] 62If he refrains from doing it in the presence of a distinguished person, he does not fall into this category. [Eliyahu Rabbah, Mishnah Berurah] (according to some authorities, even if it is only a Rabbinic prohibition),63Shulchan Aruch 385: 3 (Rashi, Tosafos etc.). See Tiferes Yisrael that even if he handles muktzeh in public he is in this category. See Bi’ur Halachah who rules that even those poskim who say that ordinarily he is not considered an apostate if he violates rabbinic prohibitions of Shabbos, agree that regarding this Halachah, he is considered as one. [Mishnah Berurah] is considered as a non-Jew, and you must rent his premises from him.
תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)