In the first open criticism from a senior Congress leader in his home State of Kerala, K. Muraleedharan on Tuesday targeted Shashi Tharoor over his recent praise for Prime Minister Narendra Modi, calling the remarks “quite disgusting.”

Addressing reporters, Mr. Muraleedharan said it was troubling that a member of the party’s working committee would continue to praise a political rival, especially during election season.

“He is a member of the working committee. It is quite disgusting that a member of the working committee continues to praise the political opponent of the Congress,” he said.

Mr. Muraleedharan’s comments came a day after Mr. Tharoor, in a newspaper article, described Mr. Modi’s “energy, dynamism, and willingness to engage” as a “prime asset” for India on the global stage, adding that the Prime Minister deserved greater support.

Mr. Tharoor’s praise for Mr. Modi came at a time when the Congress has consistently been attacking the BJP-led Centre over its foreign policy, alleging that Indian diplomacy is being “shattered” and the country stands “isolated” globally.

Asked whether disciplinary action was needed against Mr. Tharoor, he replied, “Whether action should be taken or not—let the high command decide and inform us.”

Speaking in Thiruvananthapuram last week, Mr. Tharoor said he had differences of opinion with some in the party leadership but refused to speak about those in light of the Nilambur Assembly byelections. The veteran leader said the Congress, its values, and its workers are very dear to him.