Yulia Tymoshenko, the former Ukrainian prime minister and current opposition leader, said her Batkivshyna party will never unite with other parties which call themselves opposition but in fact are controlled by the ruling Party of Regions, RIA Novosti reported.
"They are departments of the Party of Regions. Can we unite with the Party of Regions' departments?" Tymoshenko said in an interview with the TBi channel late on Thursday, without specifying which exactly parties she was speaking about.
Tymoshenko moved to the opposition after her government was dissolved in March 2010 following presidential elections that she narrowly lost to Viktor Yanukovych, then Party of Regions head. She has strongly criticized Yanukovych's government, accusing it of bowing down to Russia and betraying Ukrainian national interests.
The Ukrainian opposition has been divided since last year's presidential campaign as many its members stood as candidates in the election.
Leaders of several Ukrainian opposition parties announced in January that they were in talks on uniting into one big opposition force intended to counterbalance the existing "leftist" opposition of Yulia Tymoshenko.
Later in January, speaking during celebrations of the Ukrainian Unification Day in downtown Kiev, Tymoshenko called on the opposition to join forces to challenge Yanukovych.
"We must unite. Our chance is the next parliamentary democratic election," she said.
Ukraine will hold the next parliamentary election in 2012.