The strongest reaction came from Polish President Bronisław Komorowski, who said yesterday (3 May) that a Western boycott would send the former Soviet republic back into the arms of Russia.
But Russian President-elect Vladimir Putin said also yesterday that he opposed a boycott, saying that "under no circumstances should one mix politics...with sports."
Led by Germany, leaders of several EU countries have called off scheduled visits to Ukraine during the Euro 2012, which starts in just over a month, in protest at Tymoshenko's treatment under the rule of President Viktor Yanukovich.
Austrian Foreign Minister Michael Spindelegger said on Wednesday that no Austrian government official would attend any matches held in Ukraine.
The EU has condemned Tymoshenko's conviction as an example of selective justice and warned Ukraine that its members would not ratify agreements on political association and free trade as long as she remains in prison.
European Commission President José Manuel Barroso, who is a known football fan and whose national Portuguese team will play against Germany on 9 June in Lviv, has no plans to visit Ukraine, his spokesperson said. According to AFP, none of the remaining 26 EU Commissioners will attend.
Poles send warning to Ukraine
But Poland also sent a message to Ukraine, warning that the country's reputation would "suffer dramatically" if no humanitarian solution for the case of Tymoshenko was found.
The imprisonment of Tymoshenko, who helped organise the June soccer championships while in office and is the main political rival of Ukrainian President Viktor Yanukovich, has called into question Kyiv's efforts to move closer to the European Union.
"I have left Ukraine's prime minister and president in no doubt that the [Tymoshenko] case ...is a test of credibility for the present Ukrainian authorities and that the reputation of Ukraine would suffer dramatically if it does not find a solution that we deem civilised before the European championship," Polish Prime Minister Donald Tusk said, as quoted by Reuters.
"I think the calls for a boycott are inappropriate. I understand the politicians who sympathise with Yulia Tymoshenko, but nothing stands in their way to express this sympathy in a clear way during the championships," Tusk said.
Mixing sports and politics
In the meantime, the Ukrainian foreign ministry described the "attempts to politicise sport events" as "destructive".
"Calls to boycott the championship will mean in practice undermining the image of this grandiose sport event and harming interests of millions of ordinary Ukrainians, who vote for different parties or who are not interested in politics whatsoever," the ministry states.
Calling for keeping politics away from sports, Kyiv claims that a successful hosting of the championship would become a victory "not for certain political actors, parties or ideologies bur rather for all Ukrainians and Poles", while a failure would be "a loss for millions".
"The attack on this big dream undermines not only the chance of Poland and Ukraine, but of all former members of the socialist camp, to prove that by their economic, human and scientific potential they are already ready to change from Europe’s debtors into new engines of its development," the foreign minitry stated.
The term "socialist camp" was used under Communism to designate the countries of the former Warsaw Pact. Ukraine was a Soviet republic at that time and Poland was a Warsaw Pact member until it was disbanded in 1991. It joined NATO in 1999.