Eurovision organisers have threatened to ban Ukraine, this year’s host country, from future competitions if it maintains its refusal to let a Russian singer enter its territory to take part in the song contest.

Ukraine has barred the Russian contestant, Yuliya Samoilova, from entering the country for three years on the grounds that the 27-year-old “illegally” entered Russian-annexed Crimea to perform at a concert in 2015.

Ukraine bitterly contests Russia’s 2014 annexation of Crimea, which it considers part of its territory.

The head of the European Broadcasting Union, Ingrid Deltenre, has informed Ukraine that it was “unacceptable” to ban Ms Samoilova, who has used a wheelchair since childhood as a result of a reaction to a vaccine.