Kiev: Former Ukrainian prime minister Yulia Tymoshenko on Tuesday officially launched her bid for the country's presidency, with polls showing her as the frontrunner.
"I'm running for the presidency," she told a session of her nationalist Batkivshchyna (Fatherland) party to cheers from the crowd.
"I've made mistakes," said Tymoshenko, who is a highly divisive figure in Ukrainian politics.
"Maybe sometimes I'm wrong, but I'm wrong sincerely," she said.
"Today we are entering a new era -- an era of success, of happiness, of enlightenment... today we begin Ukraine's journey towards real and powerful greatness."
Tymoshenko is favourite to win the March 31 vote according to the latest polls, but no candidate yet has an unassailable lead.
The 58-year-old has 16 per cent support going into the two-round election, according to surveys, ahead of incumbent President Petro Poroshenko with 13.8 per cent.
In third place is Volodymyr Zelensky, a comedian who once played the country's president in a TV show but has promised to refresh Ukraine's political system.
Tymoshenko has been a leading figure in the political scene for the last two decades, coming to international prominence through her role in the 2004 Orange Revolution.
The politician, long recognisable by her braided hair heaped atop her head in traditional style, served as prime minister twice under her protest co-leader Viktor Yushchenko. But her fortunes changed after she lost the 2010 presidential election to pro-Russia Viktor Yanukovych.
The following year she faced a string of criminal investigations and was sentenced to seven years in jail, in which she served three.
She was released in 2014 -- the day that pro-Europe, anti-corruption protests led to Yanukovych's ouster.
Tymoshenko contested that year's presidential election but came a distant second to Poroshenko, who had served in her cabinet.
Supporters say she has the iron will and anti-Kremlin credentials needed to lead Ukraine but detractors accuse her of corruption and say she may have ties to Russian President Vladimir Putin.