"I feel very sad as I speak to the media. I feel sad that politics has stooped so low in the country," Atishi said.
"When Gambhir joined politics, I told him that good people are important for politics. But he and his party have shown how low they can go," she said, referring to pamphlets circulated with newspapers in the constituency.
"I am not in politics for money or fame," said Atishi, who has played a key role in reshaping the school education system in the capital.
Atishi became emotional and broke down. "If Gambhir can stoop so low to defeat a strong woman like me, how can he ensure security for women as an MP?"
Deputy Chief Minister Manish Sisodia added: "Gautam Gambhir circulated derogatory pamphlets about Atishi in East Delhi. The language in this pamphlet is so abusive that anybody who reads it will feel ashamed."
He said when Gambhir played cricket for India, the nation clapped for him.
"But we never in our worst dream thought that this man would stoop this low to win an election," Sisodia added.
Outraged by the allegations, the former cricketer came down hard in his defence on AAP chief and Delhi CM Arvind Kejriwal and tweeted, "I abhor your act of outraging a woman’s modesty @ArvindKejriwal and that too your own colleague. And all this for winning elections? U r filth Mr CM and someone needs ur very own झाड़ू to clean ur dirty mind."
In his accompanying tweet, Gambhir said he was ready to quit politics if the allegations against him were proved. "I declare that if its proven that I did it, I will withdraw my candidature right now. If not, will u quit politics?"
Gambhir said he was ashamed to have a chief minister like Kejriwal.
(With additional information from IANS)