"Manmohan Singh must seriously introspect as to how his tenure impacted on the institution of prime minister. Did he have the last word on all subjects? Or is it the system of the original Communist states that was operating, where the party general secretary was always more important than the head of the government," Jaitley wrote in his blog.
"Prime ministers are known not by the number of years they have spent in office, but by the footprints they leave behind," Jaitley said, attacking the prime minister.
The comments came after the release of a book - The Accidental Prime Minister - by the prime minister's former media adviser Sanjaya Baru Friday that has raked up a controversy.
"Sanjaya Baru's book only confirms what the country ordinarily suspected. The prime minister has to take most of its decisions approved and ratified from the Congress president. Amongst various institutions which have been dwarfed in the UPA regime, the principal one was the office of the prime minister itself," Jaitley wrote.