A high court in Kiev is hearing her the appeal of Ukrainian opposition leader Yulia Tymoshenko on Tuesday against conviction and seven-year jail sentence imposed last year on charges of selling out the national interest as prime minister by signing a disadvantageous gas deal with Russia.
The trial and her conviction caused outrage among Western governments which say it smacked of "selective justice" and has derailed the former Soviet republic's relations with the European Union.
The 27-member bloc has shelved agreements on free trade and political association in response and a number of European politicians have boycotted Euro 2012 matches being played in Ukraine, which is co-host of the soccer tournament.
So far, pressure from the EU has had no effect.
President Viktor Yanukovich, Tymoshenko's political foe, has said he will not intervene before all the trials and appeals are over while Ukrainian prosecutors have heaped fresh charges on her, saying they suspected Tymoshenko of involvement in a 1996 contract killing.
Tymoshenko's legal counsel showed little optimism ahead of Tuesday's hearing.
"There can be no justice for Tymoshenko, so all the hopes of Tymoshenko's defence lie beyond Ukraine's borders," said Serhiy Vlasenko, Tymoshenko's lawyer, meaning only Western pressure could bring about her release.
On Monday, a court in the city of Kharkiv adjourned further hearings into a separate tax evasion case until 10 July at the request of state prosecutors. The court ordered a medical examination of Tymoshenko, 51, in order to establish whether she is fit to attend her trial.
Tymoshenko, who is now being treated for back trouble in a state-run hospital in Kharkiv, has dismissed all charges against her as part of a personal vendetta by Yanukovich, who, in turn, says his government is merely fighting corruption.
Her medical treatment in Kharkiv meant she was not able to be present at the appeal hearing in Kiev.
The outcome of the legal proceedings could shape Ukraine's relations with the EU for the coming years.
Ukraine's co-hosting of the Euro 2012 soccer championship, which concludes with the final in Kiev on July 1, has diverted attention from internal problems. But despite being locked up, Tymoshenko has made her presence felt at Euro 2012 matches with some fans wearing "Free Yulia" T-shirts.
Because of the boycott by some foreign leaders, Yanukovich has mostly shared his VIP box at matches with political allies, local government officials and representatives of European soccer body UEFA.
Tymoshenko has been convicted for abusing her power as prime minister when brokering a 2009 gas deal with Russia which Yanukovich's government says saddled Ukraine with an exorbitant price for imports of gas on which it relies hugely for heating homes.