It looks like, it's high time the 'left' parties be designated as Anti-Nationals and be banned. Their history (points listed below) vouches for this......
(1) They got many freedom fighters arrested in the 1940's
(2) They supported the 'chinese' during the chinese invasion of India in 1962. (just this alone must be enough to classify them along with organizations like ISI ...)
(3) They have been known to support chinese and russian causes at the expense of the Indian population. Their opposition to the Nuclear Deal is just the latest instance of this.