Who may file a complaint?

The Law on the Election of the President (asof 2013, in Ukrainian)

Source: http://zakon2.rada.gov.ua/laws/show/474-14

Article 12. The followingshall be electoral subjects:

1) a voter;

2) the election commissionsestablished in accordance with this law as well as the Law “On Central ElectionCommission”

3) a Candidate for President ofUkraine, registered in accordance with this law

4) a party that hasnominated a candidate for President of Ukraine

5) official representatives, proxies and official observersof political parties (blocks of parties), the subjects of the electoralprocess, as well as of the Candidates for President of Ukraine.

The Code of Administrative Proceedings ofUkraine (as of 2013, in Ukrainian)

Source: http://zakon3.rada.gov.ua/laws/show/en/2747-15/page6

Article 172. 1. Thesubjects of the respective electoral process (other than the electioncommission), the referendum initiative group, other subjects initiatingreferendum may appeal against decision, actions or inaction of electioncommissions, referendum commissions, members of these committees.

2.Voter (citizen who is eligible to vote in the respective election orreferendum) may appeal the decisions, action or inaction of the electioncommission, referendum commission, members of these committees, if such adecisions, action or inaction violates voting rights or interests toparticipate in the electoral process or the referendum process.