Complex sentence: The Jewish Socialists' Group (JSG) is a Jewish socialist collective in Britain, that was founded in Manchester/Liverpool in the mid- 1970s as lobby group campaigning against the fascist National Front and for the left to relate more positively to Jewish issues.
Split into simpler sentences: The Jewish Socialists' Group (JSG) is a Jewish socialist collective in Britain, formed in the 1970s. The JSG was founded in Manchester/Liverpool in the mid- 1970s as lobby group campaigning against the fascist National Front and for the left to relate more positively to Jewish issues.