Batkivschyna lawmakers Volodymyr Aryev, Volodymyr Bondarenko and Dmytro Andrievsky.
United Opposition is considering formation of a single party.
"I very clearly said united candidate, united faction and united party. Should anyone go against this course, we will not move towards victory," head of the council of the Batkivschyna United Opposition and leader of the Front for Change Party Arseniy Yatseniuk told reporters on Friday
One of the leaders of the Batkivschyna Party, Mykola Tomenko, for his part, said that the formation of a united party "is a strategically right idea, and we supported it."
"There must be a serious strategic project to create a European political party," Tomenko said.
According to him, the creation of a united party should be discussed within its member parties and among experts. Tomenko stressed the position of imprisoned Batkivschyna Party Leader Yulia Tymoshenko should be taken into account in this matter.
"Therefore I do not see any possibility to realize this project within a month or two. I believe that we should address this issue responsibly," he added.
The opposition leader noted that all the previous attempts to create a united party had so far failed.
"Therefore it is better to go through the whole preparatory period and be ready for the establishment of such a party," he said.
At the same time, he did not say who could lead such a party.
"We will decide when we have created it," he said.
"As for the united party, this is a long process, and I think that if it is created, then Tymoshenko will most likely lead it," Tomenko added.
A new law on the parliamentary elections in Ukraine entered into force in December 2011. It prohibited blocks of parties to participate in parliamentary elections. On April 23, 2012, the Front for Change, the Batkivschyna All-Ukrainian Union, the Popular Rukh of Ukraine, the People's Self-Defense, the For Ukraine! Party and the Reforms and Order Party announced the creation of the united opposition.