Complex sentence: Under Mannix's influence Wren was fiercely anti-Communist, and after the war he was often accused of using his wealth to support politicians who opposed Communism and defended Catholic interests, but he equally accused of using them to protect his business interests, both legal and illegal.
Split into simpler sentences: Under Mannix's influence Wren was fiercely anti-Communist, and after the war he used his wealth to support politicians who opposed Communism and defended Catholic interests. In return he expected them to protect his business interests, both legal and illegal.