"The sudden passing away of senior leader Gurudas Kamatji, is a massive blow to the Congress family. Gurudasji helped build the Congress party in Mumbai and was greatly respected and admired by all. My condolences to his family in their time of grief. May his soul rest in peace," Gandhi, who is in Germany, said in a tweet.

Congress spokesperson Randeep Singh Surjewala also expressed grief over the death of the former union minister.

"Shocked and deeply anguished to learn about the sudden demise of Senior Congress Leader Gurudas Kamatji. No words are enough to describe the sense of loss. My deepest condolences to his family, friends and followers. I pray for the departed soul," Surjewala said in a tweet.

Kamat died in a private hospital here following a massive heart attack. He was 63.