The Ukranian opposition leader before and after her imprisonment

European leaders are threatening to boycott the forthcoming Euro 2012 football tournament over the treatment of Ukranian opposition leader Yulia Tymoshenko.

The EU Commission president José Manuel Barroso and justice commissioner Viviane Reding have both said they will not attend the championship because of the treatment of the jailed former Ukrainian prime minister.

On Sunday it was reported by Der Spiegel that German chancellor Angela Merkel will also boycott the championship, which Ukraine are co-hosting with Poland, in protest at her treatment.

The 51-year-old Ukranian opposition leader is in prison on abuse-of-office charges which are widely contested. Tymoshenko is on hunger strike and has claimed she has been beaten by prison guards.

Ukraine hit back at Germany's jibe at their human rights record, accusing them of cold war tactics and the politicisation of sport.

Foreign ministry spokesman Oleg Voloshyn said "we would not like to think that the political leaders of Germany are capable of reviving the methods of the Cold War and making sport a hostage of politics."

Tymoshenko, who was prime minister between 2007-10, was pictured on Friday with bruises on her abdomen, which she claims were caused by guards punching her in the stomach.

Her daughter Eugenia Tymoshenko has said she is "intense pain" and prison officials are threatening to force feed her.

Tymoshenko, a rival of Ukranian President Viktor Yanukovych, denies the abuse of power charges.

Human Rights Watch has criticised Ukraine for Tymoshenko's imprisonment, saying the judicial system lacked impartiality and risked undermining public confidence in its independence.