Reacting against Natwar Singh's statements, Mrs Gandhi said, "When I will write my own book, then the truth will come out."
Continuing her statement, Mrs Gandhi also added, "What can I say when asked, are you hurt? I have seen my husband getting assassinated... my mother-in-law getting killed by bullets. Lot many people say many things about us."
Former External Affairs Minister K Natwar Singh in his upcoming book revealed many shocking information about Gandhi family and their party. 83-year-old Singh's book -- One Life is Not Enough: An Autobiography will be released soon.
Singh, who quit Congress in 2008 after he had to resign from the UPA-I Government in 2005 in the wake of the Iraqi food-for-oil scam, claimed Rahul was afraid that Mrs Gandhi would be killed like his father Rajiv Gandhi and grandmother Indira Gandhi if she would become PM.
Singh also claimed that it was not Sonia's "inner voice" that prevented her, as she had stated at the time, to take up the PM's post. The former minister also claimed that Mrs Gandhi along with her daughter Priyanka Gandhi Vadra had approached him not to disclose such sensitive information in his book.
Singh, during one interview with TV news channel, was quoted as saying, "Rahul was totally against her mother becoming Prime Minister. He said she would be killed like his father and grand mother and as a son he would not allow to become the PM. He was very adamant."
Speaking about former Prime Minister Manmohan Singh's relation with Mrs Gandhi, Natwar Singh endorsed Manmohan Singh's former media adviser Sanjay Baru's claim that it was Mrs Gandhi and not the former PM who used to take the final call regarding any decision of the government.
He also disclosed that the then Vice President Shankar Dayal Sharma was Sonia's first choice as the Prime Minister in 1991 but Sharma, who then became President, declined the offer due to his poor health. It was then she chose PV Narasimha Rao whom she never knew and they could never share warm relations, he said.
Former Prime Minister Rajiv Gandhi was killed in a LTTE suicide bomb attack in 1991 in Sriperumbudur, near Chennai, while his mother Indira Gandhi, also a former PM, was gunned down by her Sikh security guards at her residence here in 1984.
To a question whether left to herself Sonia would have accepted the PM's post after the Congess-led UPA came to power defeating BJP-led NDA in 2004, Natwar Singh said, "it is difficult to answer".
Singh, whose son is a BJP MLA from Rajasthan, rejected the charge that there might have bitterness and revenge in him for the way he was dumped by Gandhis and said he never spoke a word against Sonia in public but "it is important to tell facts as you know them".
"She is a public figure. She is the most important politician in India... She is every biographer's dream. She is a historic figure," he said, adding that such figures have no "privacy".
When asked what if his claim that Rahul's opposition was behind her decision to not become the Prime Minister was denied by Manmohan Singh and Dubey, he said, "Of course they will. I am aware they will".
He then added, "They could have said it and got away with it if Sonia and Priyanka had not come to me. Period... They did not come to have coffee with me. They did not come to have lunch with me".
He also rated Sonia higher than Rajiv as a politician, saying she is tougher than him. "He was very large-hearted. You cannot take liberties with her," he said.