In a lengthy statement, Congress dwelt at length over the book by the former media advisor of Prime Minister Manmohan Singh, dubbing his account as "baseless and riddled with contradictions."
He had no privileged access or inside knowledge, the Congress statement said.
"The political relationship between PM Manmohan Singh and the Congress President is an inspiring example of the great democratic tradition of selfless cooperation of political leaders in the best interests of our nation, established and fostered in the Congress party by Mahatma Gandhi," it said.
The party also questioned the timing of the release of Sanjay Baru's book 'Accidental Prime Minister - The Making and Unmaking of Manmohan Singh' and former coal secretary P C Parakh's book 'Crusader or Conspirator Coalgate and Other Truths'.
At the AICC briefing, chairman of the media department, Ajay Maken termed as unfortunate the timing of the release of two books and alleged that the authors have played into the hands of the political opponents of the Congress by releasing the books in the midst of elections.
On Sanjay Baru's book, Congress said, "Given the timing of its publication and its prominence in the media, his book must qualify as mother of all plants".
Dismissing allegations of differences between Prime Minister Manmohan Singh and Gandhi, Maken said that both have the "best of relations and trust among each other".
In Lucknow, Congress general secretary and spokesman Shakeel Ahmad termed the release of books by Baru and Parakh as a "conspiracy" against Congress.
The Congress statement came close on the heels of BJP' PM candidate Narendra Modi latching on to the book to mock at Singh and targeting Sonia Gandhi and Rahul Gandhi, saying they wielded the real power instead of the PM.
"He was not at fault and was unnecessarily criticised. All the fault lies with the mother and son (Sonia and Rahul)," Modi said addressing a rally at Bhagalpur in Bihar.