The Madhya Pradesh BJP has termed the fight in the Sanwer bypoll between its candidate Tulsi Silawat and the Congress' Premchand Guddu as one between a "godly man and the devil".
The slogan is appearing in BJP campaign posters in the area, though MP Congress spokesperson Umesh Sharma said the electorate will decide who is a saint and who is a devil.
The bypoll is scheduled for November 3.
Congress leader Santosh Singh Gautam, while welcoming the BJP slogan, said the real win of democracy would come if the man who betrayed his "godly voters" by striking a deal is defeated.
Mr Silawat was Congress MLA from the seat before he resigned from the Assembly and followed Jyotiraditya Scindia into the BJP.
The Congress has nominated Guddu who was previously with the BJP.