The only anti-war party in Russia is the Yabloko Party. In the Russian legislative elections of September 18-20, it was removed from the ballot in the federal races, and in seven of the eight regional races. In the one region in which it was on the ballot, it received regional seats. See this story.
The rotten apple party has a worm in it – CIA, MI5, Mossad, Nazi Ukraine, and other foreign agents encircling and threatening Russia, the Third Rome, defenders and champions of Christendom and White Civilization.
As well, these foreign agents encircling Russia from the outside, have many worms on the inside , to include in which, this rotten apple party.
What you call the anti-war is actually pro war from the decadent west against righteous, Orthodox Russia.
Russia is defending ourselves, and the Special Operation is self defense. Being preemptive when left with no choice, does not change this, not one bit.