выкрест(So by becoming a "Christian", Boris Abramovich Berezovsky ceased being "one of his own" and acquired the official status of vykrest (convert from Judaism), as such "refuseniks" are called in Jewish circles.)
отказник(Synonym: otkaznik; One of the Jewish citizens of the former Soviet Union who were refused permission to emigrate: In 1974, a handful of brave Soviet Jews haunted foreign embassies in Moscow hoping for exit visas. Refuseniks, they were called; the Brezhnev Government wouldn't let them out.wiktionary.org)