* Tymoshenko addresses Independence Square from wheelchair
* Wins mixed welcome; cheers and whistles
* Release sets up possible run for presidency (Updates with speech, quotes, whistles,)
By Alessandra Prentice and Matt Robinson
KIEV, Feb 22 (Reuters) - Ukrainian opposition leader Yulia Tymoshenko was freed by her jailors on Saturday during the dramatic ouster of President Viktor Yanukovich, but an emotional speech from her wheelchair won a mixed response from Kiev's Independence Square.
Cheers and whistles from anti-government protesters reflected the polarising nature of the 53-year-old former gas magnate, who co-led Ukraine's 2004-05 Orange Revolution but disappointed supporters as prime minister.
Her release sets up a possible run at the presidency in an election called for May 25.
To shouts of "Yulia! Yulia" from supporters, and sporting her distinctive blond braid, Tymoshenko was driven out of the hospital in the northeastern city of Kharkiv where she had been held under prison guard while she had treatment for a bad back.
Within hours, the former prime minister was carried in her wheelchair onto a stage on Independence Square, where 82 people were killed this week in the worst violence in more than 22 years of Ukrainian statehood.
Thousands had packed the square after parliament voted to oust her arch-enemy, President Viktor Yanukovich. Having abandoned the capital, Yanukovich denounced what he said was a "coup d'etat" and said he remained the lawful president.
"You have no right to leave the Maidan (square)... Don't stop yet," Tymoshenko told the crowd, wrapped in a thick anorak as rain fell.
She looked tired after emerging from more than two years in prison or hospital, apparently shaking with emotion.
Showing glimpses of the fiery oratory that drove her to power, Tymoshenko shouted: "This is a Ukraine of different people. The ones who died on Maidan are our liberators, our heroes for centuries."
"DICTATORSHIP HAS ENDED"
The response, however, was mixed. Tymoshenko is a divisive figure in Ukraine, commanding devotion from some and contempt from others. Many Ukrainians have become disillusioned with a discredited political class, widely seen as a corrupt and elitist.
Small pockets of the crowd clapped and sang Tymoshenko's name, but the chants did not catch on. Whistles could be heard. Others listened silently.
"She's a symbol," said 54-year-old Tamara Makovetska from Kiev. "But elections will decide. We will decide, at least I hope we will decide."
Anna Gladilina, a pensioner holding a Ukrainian flag, was stunned by Tymoshenko's comeback.
"She's doesn't believe in politics but in the people," she said. "It's a miracle she's here.
Protesters have rallied on the square since November last year, when Yanukovich spurned a deal on closer ties with the European Union under pressure from Russia.
The EU brokered a peace deal on Friday, calling for an election by year-end, but protesters made clear they wanted Yanukovich out immediately.
In a day of high drama, parliament voted to remove him from office and set an election for May 25. The president had fled the capital, abandoning his offices and residence.
"Our homeland will from today on be able to see the sun and sky as a dictatorship has ended," Tymoshenko told reporters after emerging from hospital.
Tymoshenko was jailed in 2011 for abuse of office over a natural gas deal with Russia, but her supporters and Western leaders regarded her as a political prisoner.
"I voted for her before as the only real alternative," said Oleh, a 50-year-old taxi driver from Kiev, "but she disappointed."
"We need to get rid of all the politicians of the last 22 years. Those who led the revolution, the middle class, the 'self-defence' protesters, those are the kind of honest people we need." (Additional reporting by Timothy Heritage and Pavel Polityukm, Writing by Matt Robinson, Editing by Timothy Heritage)