On the festival's last day, Tharoor said: "Protests can be defused if Narendra Modi and Amit Shah say - 'We are dropping idea of NRC', that they will no longer ask NPR enumeration & go to every door asking - 'where were your father and mother were born' and ask for documentary proof."
However, the duo are not ready to give such assurances, he added.
Tharoor's comments, made on the last day of the four-day annual literary festival, are the second time in two days that the controversial law has figured there.
On Saturday, his party colleague Kapil Sibal had spoken about the act at the same venue.
Sibal had contended that there is no way a state can deny the implementation of the Citizenship Amendment Act (CAA) when it is already passed by the Parliament, and went on to claim that doing so would be "unconstitutional".
Earlier, on Friday, eminent historian Ramachandra Guha had courted controversy by saying that kerala has done a disastrous thing by electing a "fifth-generation dynast" Rahul Gandhi.
The political statements coming in quick succession appear to have diverted the public gaze from the principal objective of the Keral Lit Fest, which is to promote literature and culture.
The Kerala Literature Festival is among the major cultural gatherings in the country and region, hosting literary, cultural and social celebrities over the years.
( With inputs from IANS )