In the decision in the case Stretch vs The United Kingdom the European Court of Human Rights found infraction of Article 1, Protocol 1 to the Convention for the Protection of Human Rights and Fundamental Freedoms in situation where national courts considered the clause on land lease agreement extension void. There are two trends in application of this decision by Ukrainian courts. On the one hand, courts often come to wrong conclusion that rendering invalid any agreement which have transferred property from the state or a local community to a private person due to violations committed by authorities is forbidden. To the contrary, often the reasoning in the «Stretch…» case is being declared not applicable at all. The author is of the opinion that the decision in the «Stretch…» case emphasizes on one of the necessary preconditions of the lawfulness of interference into property right — its proportionality. Proportionality of interference and «an equitable balance» must be established on each situation. Interference is not justified if it is a response to purely formal violations of law; to the contrary, the «Stretch…» decision is not an obstacle for claiming property which has been taken from the original owner unlawfully and not in a good faith.