Complex sentence: The Revisionists, especially its secret radical branch, Brit Habiryonim, expressed extreme criticism in Mapai's willingness to confer with the Nazi government over German Jews' expedited emigration to Palestine.
Split into simpler sentences: The Revisionists, especially its secret radical branch, Brit Habiryonim, expressed extreme criticism in Mapai's willingness to confer with the Germans. They were also against Mapai's interest in negotiations with the Nazi government over German Jews expedited immigration to Palestine.