A day after the Election Commission sought evidence from the Congress over a graft claim against the BJP in an advertisement, Rajya Sabha MP Kapil Sibal on Sunday called on the poll watchdog to seek proof from Prime Minister Narendra Modi on his allegation that the Congress is taking part in backdoor political negotiations with those linked to terrorism.

The Election Commission has issued a notice to the Karnataka Congress over its "corruption rate card" advertisements published in newspapers targeting the BJP, and sought "empirical evidence" to prove its allegations by Sunday evening.