Former Ukraine’s PM Yulia Tymoshenko has announced she is planning to run for presidency in May elections.
Yulia Tymoshenko was released from prison in February following the ousting of President Viktor Yanukovych, after three years in jail.
She has already served twice as prime minister and ran for president in 2010.
Yulia Tymoshenko was a major figure in the 2004 “Orange Revolution” that toppled Viktor Yanukovych’s first administration.
She said she would stand as “a candidate for Ukrainian unity”.
Yulia Tymoshenko told reporters that she had earned the right to be considered a candidate who was against corruption.
She narrowly lost the 2010 presidential election to pro-Russian Viktor Yanukovych.
Yulia Tymoshenko was imprisoned in 2011 for corruption linked to a gas deal she brokered with Russia as prime minister in 2009.
Her supporters say the case was politically motivated and instigated by her rival Viktor Yanukovych.
On Monday Yulia Tymoshenko denied the authenticity of a taped conversation in which she allegedly called for Russia to be turned into “scorched earth” and for ethnic Russians in Ukraine to be killed.
Yulia Tymoshenko said the recording, which featured prominently on Russian news reports, was produced by Russia’s security services.
Former boxer Vitaliy Klitschko and chocolate tycoon Petro Poroshenko are also expected to take part in the presidential election.
Opinion polls suggest Petro Poroshenko, who is one of Ukraine’s richest men, is currently the most popular candidate.
Ukraine’s presidential election is expected to take place on May 25.