"Kalyan Singh & Yedyurappa back in BJP -deadly cocktail of corruption and communalism. BJP's blueprint for India's future," CPI(M) leader Sitaram Yechury tweeted in the micro-blogging website twitter.
Former Uttar Pradesh Chief Minister Kalyan Singh rejoined BJP on Sunday and was appointed as its national vice president, marking his rehabilitation in the party.
In January, former Karnataka Chief Minister BS Yeddyurappa returned to BJP and merged his Karnataka Janata Party a year after he walked out of the party alleging betrayal.