The EC on Monday had issued a notice to Jayalalithaa for prima-facie violation of the Model Code of Conduct for announcing new schemes ahead of December 4 Yercaud assembly bypoll.
The Commission asked her to reply to its notice by 5 PM on Tuesday.
The Model Code of Conduct instructs that no new schemes should be announced after poll dates are delared. The announcements so made are violative of sub para (vi) of para "II-Party in Power", of the Model Code of Conduct.
Jayalalithaa has been accused of announcing new schemes for the area where bye-elections are being held.
"The Commission has decided to afford you an opportunity to explain your stand why action should not be taken against you for the aforesaid violation of MCC. Your reply in the matter must reach the Commission by 5 PM of 3rd December, 2013," the EC notice said.