Earlier on Thursday, the acting head of the Ukrainian Security Council, Valentin Nalivaychenko, said the council is currently investigating reports about a possible threat, without giving any details.
Raisa Bogatyreva, the head of the party's faction in the Supreme Rada, said "any political speculation surrounding this [information] is unacceptable."
She said similar statements regarding Ukrainian politicians should not be made in future.
She also called for members of opposition factions in the Supreme Rada to join the "anti-crisis" coalition comprising the Party of Regions (185 deputies), the Socialist Party (31 deputies), and the Communist Party (21 deputies).
She said many members of the pro-presidential bloc Our Ukraine and Yulia Tymoshenko's bloc (BYT) disagree with "the revolutionary methods of their leadership" and could move over to the "anti-crisis" coalition.
"I am convinced that the opposition should stop its guerrilla tactics with the authorities and unite around the policies and ideas announced by [Prime Minister] Viktor Yanukovych," she said.
The BYT and Our Ukraine factions in the Ukrainian parliament have 125 and 79 deputies, respectively.
In late February, both factions signed a unity accord and pledged to unite all democratic forces, both within and outside parliament, into the united All-Ukraine democratic movement.
