If people of Kerala want to succeed in the modern world of liberalisation and globalisation, they should learn English well, he said at a two-day international conference on "Curricular Reforms and Class Room Practices in English" on Saturday night.
"Denial of opportunity to learn English to our children would be tantamount to destroying their future," he said, adding learning English should not be the privilege of a few.
Mr Tharoor, a former United Nations diplomat, however, said Malayalam should certainly be the first language of people of Kerala and English the second language, adding knowledge of English would be a passport to economic, social and educational advancement.
Noting that more Keralites were forced to go to different corners of the world as the state did not offer large scale job opportunities, he said hence English was more important to Malayalis than it was to Biharis or Tamilians.
He said re-organisation of states on linguistic basis had killed the 'multi-culturalism' which prevailed in the country till then, though it had certain advantages on the other.
Mr Tharoor recalled that late VK Krishna Menon had, 40 years ago, successfully contested Lok Sabha polls from Thiruvananthapuram, the constituency represented by him now, with all his speeches in English throughout electioneering.
"Had I delivered all speeches in the election campaign in 2009, I would have lost even my deposit," said Mr Tharoor, whose candidature then was opposed by a section on the ground that he was not well versed in Malayalam.
Congress MP PC Chacko was among others who spoke in the conference organised by the State Institute of English and the Sarva Siksha Abhiyan at nearby Mulamkunnathukav.