Eurovision tension: Ukraine entry angers Russia
Questions have been raised over whether Ukraine's choice for Eurovision is too political as it refers to Stalin's deportation of the Tatar minority from the Crimea.
Jamala's song "1944" was chosen to represent Ukraine at the contest in Stockholm in May, after a public vote on Ukrainian national TV.
But does it fall foul of the competition's "no politics" rules - and which countries have got away with it in the past?
BBC News takes a look at some past entries.