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

Source:

Article 15, Law "On Political Parties in Ukraine" (2001)

(UK)

Не допускається здійснення внесків на підтримку політичних партій:
2) державними та комунальними підприємствами, установами та організаціями;
3) юридичними особами, в яких не менше 10 відсотків статутного капіталу або прав голосу прямо або опосередковано належать державі, органам місцевого самоврядування;
4) юридичними особами, кінцевими бенефіціарними власниками (контролерами) яких є особи, зазначені у підпунктах "а", "в"-"і" пункту 1 та у підпункті "а" пункту 2 частини першої статті 3 Закону України "Про запобігання корупції".

(EN)

Donations in support of political parties shall be prohibited if they are made by:
2) state-owned and local self-governance-owned companies, institutions and organizations;
3) legal entities in which at least 10 per cent of the authorized capital or voting rights are directly or indirectly owned by the state or local self-governance bodies;
4) legal entities whose ultimate beneficiary owners (controllers) are persons specified in subparagraphs “a”, “в”-“i” of paragraph 1 and in subparagraph “a” of paragraph 2, Part one, Article 3 of the Law of Ukraine “On Prevention of Corruption”.
Available at: 

https://zakon.rada.gov.ua/laws/show/2365-14#Text

Ukrainian law doesn't ban corporate donations to political parties. But there are some limits for certain legal entities.

In national (parliamentary and presidential) elections, restrictions are applied under the Law “On Political Parties in Ukraine,” which also applies during the inter-election period. In particular, Article 15 of the Law “On Political Parties in Ukraine” refers to: Part 1, 3 of Article 96 of the Electoral Code of Ukraine (restrictions on entities in presidential elections), Part 2 of Article 96 of the Electoral Code of Ukraine (restrictions on the size of contributions in presidential elections); Parts 1 and 3 of Article 152 of the Electoral Code of Ukraine (restrictions on entities in parliamentary elections), Part 2 of Article 152 of the Electoral Code of Ukraine (restrictions on the size of contributions in parliamentary elections)