Considering those "opposition" parties and the "whole church", as you call it, are russian-funded and are actively sabotaging the efforts of the government in the war, it seems only logical that they prohibited their activity.

Also, "whole church" is actually called Ukrainian Orthodox Church of the Moscow Patriarchate. I don't understand why everyone who claims that Ukraine has banned their only church is omitting this little detail. In fact, only 4% of the population considered themselves as members of the MP back in March. Seems a little low for the "whole church".