The BJP on Sunday called Manmohan Singh the "weakest prime minister ever", and asked him to introspect how his tenure "impacted on the institution".
Commenting on the book "The Accidental Prime Minister: The Making and Unmaking of Manmohan Singh" by the prime minister's former advisor Sanjay Baru, veteran Bharatiya Janata Party leader L.K. Advani said the book endorsed what everyone knew -- that Manmohan Singh was the weakest prime minister.
"The book has officially endorsed what everyone knew... When I said I feel he (Manmohan Singh) is the weakest prime minister ever, my colleagues said he is a nice man, why do you criticise him so much," Advani said.
"I pity him, and have sympathy for him," he said.
Leader of Opposition in the Rajya Sabha Arun Jaitley said Manmohan Singh must seriously introspect as to how his tenure has impacted the Prime Minister's Office as an institution.
"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.
BJP spokesperson Ravi Shankar Prasad said the situation in the Congress was stuck between an "accidental prime minister" and party vice president Rahul Gandhi, who "did not even want to be a prime ministerial candidate".
"Rahul Gandhi says he will empower the common man. How would he do that when he could not even empower his prime minister?," Prasad asked.