Party sources said a two-day trip was being planned during which the Congress Vice President would visit Ahmedabad as well as Rajkot.
Congress has stepped up attack on Modi in the wake of Vanzara's letter slamming the state government.
Vanzara (59), a Deputy Inspector General of Police (DIG) considered close to Modi, had on Tuesday resigned from IPS service accusing the Gujarat government of failing to protect loyal police officers who fought against "Pakistan-inspired terrorism".
The Congress unit in Gujarat has called a state wide bandh tomorrow in the wake of Vanzara's letter.