"When PM is in the country, people have the right to question him," said Shashi Tharoor. (File photo)

Senior Congress leader Shashi Tharoor, who is a strong critic of the Modi-led government, on Sunday said the prime minister deserves respect when he visits foreign countries as India's representative, but when he is in the country, people have the right to question him.

"The prime minister deserves respect in foreign countries as (there) he is a representative of our nation. But when he is in India, we have the right to ask him questions," Mr Tharoor said while speaking at a session organised by the All India Professional Congress in Pune district of Maharashtra.

On the row over a common language for India, the Lok Sabha MP from Kerala said he was in favour of a three-language formula (promoting multilingual communicative abilities).

He said the BJP's ideology of promoting Hindi, Hinduism and Hindustan is "dangerous" for our country. "We need to carry on the three-language formula," he said.

Amid a heated debate over his remark that Hindi should be a common language, Union Home Minister Amit Shah on Wednesday said he has never asked for imposition of Hindi over native languages in the country but advocated its use as the second language.

He criticised the ruling BJP over incidents of mob attacks, saying they are an "insult to Hinduism and Lord Ram". "There is no difference among people (of different communities) living in Kerala. Then why it is happening in Maharashtra," he said.

Even Maratha warrior king Shivaji Maharaj had people from different communities under his rule. But he instructed everyone to respect each other, he said.

The BJP's idea of Hinduism is a "political ideology"and does not have any connection with Hinduism, the Congress leader said.