The court in Strasbourg is considering only the legality of her pre-trial detention and the conditions under which she was held. A ruling could take months.
The 51-year-old Tymoshenko, who rose to international fame as the figurehead of the 2004-2005 Orange Revolution, had been kept in permanently lit, unheated cells and tracked by surveillance cameras, her lawyers said.
"She asked me to ask you for help," lawyer Serhiy Vlasenko told the Strasbourg court.
"The only reason for her detention was to exclude her from Ukrainian political life and to prevent her from participating in the 28 October parliamentary elections," Vlasenko said.
Tymoshenko’s party, Batkivschyna (Fatherland), has appealed to the country’s Supreme Administrative Court over the administrative refusal to register the former prime minister and Lutsenko, the former interior minister, as the party's parliamentary candidates for the legislative election to be held on 28 October (see background).
Tymoshenko's seven-year sentence for abuse of office - related to her brokering a disadvantageous gas deal with Russia in 2009 - drew condemnation from Western governments, which accuse Ukrainian President Viktor Yanukovich of waging a personal vendetta against his arch-rival.
A Ukrainian high court, meanwhile, is expected today (29 August) to rule on Tymoshenko's appeal against her conviction. Analysts do not expect the court to free her, complicating ties with the West as the former Soviet republic approaches the legislative election.
Critics say the exclusion of Tymoshenko - the country's most significant opposition figure - means the election can be neither free nor fair.
"In Ukrainian courts, this does not exist. All the judges in Ukraine are now under the full control of the Yanukovich regime which is trying to destroy my mother," Tymoshenko’s daughter Yevgenia said.
Defence lawyers would have to exhaust the appeals process in Ukraine before bringing a case over Tymoshenko's conviction to the human rights court, which is under the aegis of the Council of Europe.
The court's rulings cannot be appealed and signatories must comply or face exclusion from the Council of Europe. A committee is charged with ensuring members' laws are amended to reflect rulings but delays are common.
Last month, the same court condemned Ukraine for its 2010 pre-trial detention of Yuri Lutsenko, a former interior minister under Tymoshenko, and ordered Ukraine to pay 15,000 euros to the opposition politician. The court did not rule on the legitimacy of his conviction but called his detention arbitrary.
Then, on 17 August, a Ukrainian court sentenced Lutsenko to another two years. His new sentence should not add to his prison time, but the ruling means he could remain behind bars even if the European Court of Human Rights has ruled against his previous conviction.
In tough remarks last Friday, Yanukovich said he would not negotiate integration with the EU at the price of allowing it to interfere in her case.