The complaint against the Congress leader was that he asked each party worker to "cast 10 votes" in the June 12 by-elections.
The EC gave the chief minister time till May 31 to reply to the notice, official sources said.
The YSR Congress had lodged a complaint against Kiran accusing him of violating the code of conduct which is in force for the bypolls to 18 Assembly segments and one Lok Sabha constituency. Taking cognisance of the complaint, the EC issued the notice, the sources said.
As part of his campaigning for the by-elections, Kiran had been preaching a new mantra to Congress workers, "Each one, change 10 (voters)."
When he spoke about it for the first time in Narsapur early this month, party workers were left wondering "what to change" as Kiran could not clearly explain the whole idea.
The chief minister, said to have poor command over Telugu, went on repeating the same mantra in other constituencies as well. However, his party has blamed "communication gap" for the episode.
"What Kiran actually meant was that each worker should make at least 10 people vote for the Congress but it was probably misinterpreted. It could be a clear case of communication gap," pointed out a state Congress leader, who has accompanied the chief minister on election tours.
