The book, "2014 The Election That Changed India" (Penguin/Viking), also says that Congress vice president Rahul Gandhi has failed to show any quality as a leader and is hardly respected by his own party colleagues.
"Modi is perhaps closest to Indira Gandhi in his personality driven leadership style, an imperious attitude that ensures that institutions remain subservient to the individual," the riveting 372-page book says.
"Much like Indira, Modi in power is in no mood to reach out to the opposition," says Sardesai, referring to the Bharatiya Janata Party's refusal to recognize the Congress as the leader of the opposition in parliament.
Modi, the book says, is determined to exercise tight control over the cabinet system.
"There is a certain fear factor that Modi has instilled in his cabinet colleagues," the author says, adding how a minister in the Modi government told him (Sardesai) to enter his house from the back entrance.
The unnamed minister also insisted that they do not speak in his main hall but in the garden behind the residence.
"You never know which room is bugged nowadays!" the minister is quoted as saying.
According to the book, the original list of cabinet and other ministers in Modi's government was prepared by Modi confidants Arun Jaitley and Amit Shah and then vetted by the Rashtriya Swayamsewak Sangh (RSS).
"The final touches, including portfolio distribution, were done by the prime minister himself."
According to Sardesai, Modi implicitly trusted Jaitley, now the finance and defence minister, but did not trust Sushma Swaraj, who heads the external affairs ministry.
"There was even a suggestion that Modi had elevated Smriti (Irani as the HRD minister) because he wanted to send out a message to Sushma (Swaraj) that she wasn't the only woman face of the BJP."
The book adds: "Apart from Jaitley and a few others, Modi wasn't convinced about the abilities of many of his cabinet colleagues."
In contrast to Modi, Rahul Gandhi has "singularly failed to show any quality that marks him out as a leader who can lift a struggling party", the book says.
"He is probably the first member of the Nehru-Gandhi family who doesn't even command the respect of his own party men."
According to Sardesai, dynasty alone will not sustain the Congress although the Gandhi family remains both an asset and a liability.
The Congress, badly mauled in the Lok Sabha battle, "needs to throw up a merit-driven, mass-based leadership that can usher in new ideas and energies".
Describing Modi as "a tough, dynamic politician", the book says: "Challenging him will require the Congress to move beyond its time-worn slogans and identify more directly with the aspirations of a younger, more impatient India."
The book concludes: "If a Congress under (Jawaharlal) Nehru ushered in India's republican constitution, a BJP led by Modi could well redefine the idea of India, or at least the way it is governed."