Baru's The Accidental Prime Minister has raised issues that the Congress-led UPA-II government would not have wanted to come out at, at least when elections are on.
PM's media advisor Pankaj Pachauri described the book as "an attempt to misuse a privileged position and access to high office to gain credibility and to apparently exploit it for commercial gains.
"The commentary smacks of fiction and the coloured views of the former advisor," said Pachauri.
The BJP cashed in on it. "I have been saying from day one – PM presides, Madam decides," BJP leader M Venkaiah Naidu said.
Tellingly subtitled 'The Making and Unmaking of Manmohan Singh", the book is an account of Baru's four years as advisor from 2004 to 2008, during UPA-I.
Baru says it was Gandhi who decided on cabinet berths... "The PM never questioned Sonia's right, as party president, to influence portfolio allocations," the book says.
Baru hints at machinations behind the appointments of P Chidambaram as finance minister in 2004 and Jairam Ramesh's induction in 2005. About the latter, he writes the PM asked him whether he thought Ramesh should be inducted into the government, and he replied that Ramesh ought to be more demonstrative of his loyalty to the PM if he wanted a ministerial berth.
The matter got around, and a few days later, Montek Singh Ahluwalia asked him at a party why he was opposing Jairam's induction.
He also recounts how on one occasion Ahmed Patel, the Congress leader closest to Sonia Gandhi, arrived at the prime minister's residence just minutes before Singh's letter to the President listing the names of MPs to be sworn in as ministers in a reshuffle was dispatched.
"Since the letter had been typed and signed and was ready to be delivered...it was decided that instead of wasting time retyping the letter, the new name being canvassed by Patel would be typed over an existing name, with that name being painted over with whitener. Thus was Andhra MP Subbirami Reddy accommodated into the council of ministers in January 2006, after white paint had been applied over the name of Harish Rawat, an MP from Uttarakhand, who is now the chief minister of that state."
These are politically damaging reactions, though it's very clear whose side the book is on. Baru, whose father and Singh had many close friends, is sympathetic to the PM, saying he is a "good man" and "good prime minister" who has not been credited enough for his political interventions such as getting the DMK on board in 2004 and for keeping the coalition together through his tenure.
He also implies that the Congress have had a hand in his defeat in the one time he fought the Lok Sabha elections in 1999.
It also reveals a side of the intensely reticent Singh that's little known — for instance that he has an "avuncular" relation with Sonia Gandhi who sometimes consults him about family matters.
When approached for his comment on the PMO's reaction, Sanjay Baru texted a one-liner, "I am amused!"
In the book, Baru said Sonia slowly chipped away at the authority of the PMO, created a parallel power structure and left a weakened prime minister who "allowed himself to become an object of such ridicule in his second term".
Baru, who now works with a think tank, said so weak was Singh that he also failed to defend his (Baru's) promised reappointment after the 2009 election victory as secretary in the PMO and tamely surrendered to the party's veto.
"To tell the truth, I was dismayed by the PM's display of spinelessness," Baru said of his former boss.