A tell-all book by an ex-aide to Indian Prime Minister Dr Manmohan Singh depicting him as a powerless political puppet hit bookstores, stirring new controversy in the midst of a bitterly fought election. The book paints a damning portrait of a leader who was in office - but "not in power" - while Congress party president Sonia Gandhi called the shots. Entitled The Accidental Prime Minister - The Making and Unmaking of Manmohan Singh , the book is by academic and journalist Dr Sanjaya Baru, who worked as media adviser to the prime minister until 2008. Baru said Singh decided early on to "surrender" to Gandhi and quotes the prime minister as saying he had "to accept the party president [Gandhi] is the centre of power". Critics have long charged Gandhi held the reins of power in the Singh administration but Baru's book is the first by a close adviser to Singh to make that claim. "Bit by bit, in the space of a few weeks he was defanged. He thought he could induct the ministers he wanted into his team. Sonia nipped that hope in the bud by offering the finance portfolio to Pranab [Mukherjee], without even consulting him," Baru writes. He said Singh "averted his eyes from corruption" to ensure his scandal-tainted government's "longevity". While Singh, 81, who retires after this election, maintained the "highest standards of probity in public life", he "turned a blind eye to the misdeeds of ministers". Baru portrays Singh as an eminent economist who initiated India's first round of landmark economic reforms in the 1990s. But Baru said he made one "fatal error of judgment" in "promising loyalty to [an undemocratic] hereditary succession". Singh's spokesman Pankaj Pachauri said the book "smacks of fiction" and alleged Baru misused a "privileged position" for "commercial gain".