Rabbi Shlomo Eliezer Alfandri, leader of the Sephardic community in Jerusalem (1826-1930)

I hereby make known that it is forbidden for any Jew whose forefathers stood at Mount Sinai and has a portion in the G-d of Israel and His Torah, to remain a member in the Nationalist Council, which has lifted up its hand against the Torah of Moses and desecrates the laws of the Torah brazenly. G-d forbid for any good Jew to be in their company, let alone to aid and abet these sinners in any way, shape or form.

And since the honourable [British Mandate] government has given permission to opt out of the Nationalist Council, it is a holy obligation upon all observant Jews to go as soon as possible and to opt out from the Nationalist Council while it is still possible. (Responsa Saba Kadisha 1:32)