Lawyers for jailed Ukrainian opposition leader Yulia Tymoshenko on Wednesday said they would appeal her seven year sentence on abuse of power charges to the Supreme Court of Ukraine.
Her defence said they could make the appeal based on a ruling by the European Court of Human Rights (ECHR) that detention of the former prime minister was arbitrary and unlawful.
The ECHR ruling was made on April 30 but entered into full legal force on July 30.
The appeal to Ukraine's highest instance offers another chance for Tymoshenko's release and mitigate the consequences of a case which has set back Kiev's hopes of joining the European Union.
"From today, the defence has reason to appeal to the Supreme Court of Ukraine to reconsider and cancel the politically motivated verdict," Tymoshenko's lawyer Sergiy Vlasenko told reporters. He said the appeal would be made soon.
Short of a presidential pardon, the appeal to the Ukraine Supreme Court is the final legal recourse open to Tymoshenko at home. The High Specialised Court of Ukraine in August rejected an appeal against her verdict.
On Tuesday, the Ministry of Justice stated that the decision of the ECHR was fully implemented and does not require additional obligations from Ukraine.
Tymoshenko was first detained in August 2011 and in October 2011 sentenced to seven years in jail on charges of overstepping her authority while prime minister by agreeing a gas deal with Russia.
This term has severely harmed Ukraine's relations with the European Union and is holding up the signing of an Association Agreement with the bloc.
Ukraine has set its sights on joining the European Union and such an agreement would be a first formal step on the road to membership. Kiev is hoping to sign the agreement at the EU's Eastern Partnership summit in Vilnius in November.
Tymoshenko has insisted her imprisonment was ordered by Ukrainian President Viktor Yanukovych in a bid to eliminate a dangerous opponent from political life ahead of 2015 presidential polls.
The fiery 2004 pro-democracy Orange Revolution co-leader has seen other legal troubles pile up since her conviction, including a separate trial on tax evasion and embezzlement charges while head of Ukraine's main power utility in the 1990s.
She has also been charged with involvement in the 1996 gangland-style shooting of Ukrainian lawmaker Yevgen Shcherban.