Kolkata: Senior Congress leader Shashi Tharoor on Thursday praised Prime Minister Narendra Modi for his personal graciousness despite an earlier spat, while criticising the government led by him.

Mr Modi had congratulated him after his victory in the Lok Sabha elections, Mr Tharoor said during a media interaction at the launch of his book "India Shashtra" in the Apeejay Kolkata Literary Festival. "I didn't expect him to reach out and that's why I was very impressed," he said.

Mr Tharoor, who recently accepted the Prime Minister's invitation to join the Clean India campaign, also said he had been taken aback by the Prime Minister's invitation. "It was a very gracious thing to do," he said.

"I joined because that was the cause I believed in."

Mr Modi "had not shown signs of reconciliation with an opponent before that," which had surprised him, he said.

"He and I had also clashed quite clearly and explicitly three to eight months previously when he had said something about my wife," Mr Tharoor added.

Ahead of the Lok Sabha elections, Mr Modi had taken a dig at Sunanda Pushkar at an election rally in Shimla, calling her a "Rs. 50 crore girlfriend" - a reference to the controversy over the Kochi IPL.

Mr Tharoor had retaliated, tweeting, "My wife is worth a lot more than your imaginary 50 crores. She is priceless."

The Congress leader also recalled that PM Modi had also reached out to him earlier on Twitter, but for political reasons.

Mr Tharoor had drawn barbs from his party colleagues earlier for what they perceived as support to BJP causes.

In October, he was dropped as the spokesperson of Congress on the charge that he had praised Prime Minister Narendra Modi once too often. While Kerala Congress leaders had made the allegation, party chief Sonia Gandhi had reportedly agreed.

"As a loyal worker of the Congress, I accept the decision of the party president," Mr Tharoor had said.