3. Is there a ban on corporate donations to political parties?

Article 25, Polish ACT on political parties

A political party may receive funds only from natural persons, subject to the provisions of paragraph 2, Article 24 (4) and (7), Article 28 (1) and the provisions of acts of law concerning elections to the Sejm of the Republic of Poland and to the Senate of the Republic of Poland as well as elections to the European Parliament, regarding earmarked subsidy.