In an exclusive interview with Zee News, Natwar Singh hit back at former Prime Minister Manmohan Singh's comment that he was using private conversations for commercial gain. "Manmohan Singh is a 'ghatiya insaan' (cheap person). He never had the courage to stand up to Sonia Gandhi," Singh remarked.

Former Congress leader Natwar Singh in his autobiography One Life is Not Enough, has made several revelations on the functioning of the UPA government and about its chairperson Sonia Gandhi. In his book, Singh alleges that files from the Prime Minister's Office (PMO) were passed on to Sonia Gandhi. Manmohan Singh spoke out on the issue denying any truth to these statements.

Natwar Singh was the External Affairs minister in Manmohan Singh's UPA-1 government. In 2005 the Volcker committee report named him for alleged corruption in the Oil for Food programme in Iraq. He resigned from his ministerial post and was later dropped from the party.

While the book devotes only one of its 20 chapters to the Congress leader Sonia Gandhi, it is the revelations pertaining to her that have caught the most attention. Read more.

One of the biggest revelations made has been that Sonia turned down the post of Prime Minister in 2004 under pressure from Rahul Gandhi. Rahul allegedly demanded that she decline the post, fearing that she would be assassinated like his father, and Sonia acquiesced to his wish. Read more.

Sonia reportedly visited Singh ahead of the book's launch to dissuade him from going public with his allegations. Read more.

Post the remarks made by Singh, she hit out at him saying, “When I will write my own book, then the truth will come out.” Read more.

Several Congress leaders have stepped up in defence of their party leader and called Singh's revelation 'politically motivated'.

In the interview with Zee News, Singh denies that the release of his book was timed for after Congress' defeat in the elections. “I thought Congress would get at least 80-90 seats in the 2014 elections. But in spite of the poor show I think if Sonia was removed the tally would have dropped to 4 from 44. Whereas, if Rahul was dropped it would have bagged at least 30 seats,” Singh says. "Rahul is a good man but lacks the 'fire'. Politics is not a part-time job, it is a 24x7 job."

Despite the failings of Rahul Gandhi, Natwar Singh blames Manmohan Singh for the failings of UPA's second term at the government. Singh says that he did not have the chance to speak out earlier, alleging that newspapers and magazines refused to take his articles for fear of offending Sonia. "My book is not Sonia-centric," says Singh. He says that he has written about several other leaders, including Indira and Rajiv Gandhi, but they haven't drawn the same attention.

On Rajiv Gandhi, Singh says, "Sri Lanka policy led to his assassination." Singh alleges that Rajiv Gandhi was badly advised by his advisors Arun Nehru and Arun Singh.

Watch the full interview below :