Congress vice-president Rahul Gandhi on Thursday advised partymen against launching personal attacks on political opponents.
"It is wrong to make personal attacks on opposition," news agency PTI quoted Gandhi as saying.
His remarks come at a time when the war of words between the Congress and the Bharatiya Janata Party (BJP) is intensifying in the run-up to the 2014 Lok Sabha elections.
Congress leader Mani Shankar Aiyar had recently triggered a controversy by attacking BJP's prime ministerial candidate Narendra Modi over his humble past as a tea seller.
Aiyar had said at a party meeting, "If he (Modi) wants, he can come and sell tea here at the AICC (All India Congress Committee) meet... Narendra Modi cannot become the prime minister in the 21st century."
Modi, on his part, had hit back by accusing the Congress' top leadership of practising dynasty politics. "The traditions in which they have grown up... their minds are feudalistic," Modi had said, apparently referring to the Nehru-Gandhi family.