'The party strongly disapproves the statement of the minister. It is unacceptable, not respecting political or any other sensibilities,' said Congress spokesperson Jayanthi Natarajan.
However, the party high command would decide whether to act against Tharoor.
Tharoor on his page on the micro-blogging site Twitter, was asked, 'Tell us minister, next time you travel to Kerala, will it be cattle class?'
'Absolutely, in cattle class out of solidarity with all our holy cows,' he replied.
As a part of the Congress austerity drive, Tharoor and External Affairs Minister S M Krishna were asked to vacate their five-star hotel accommodations where they were staying at their own expenses.
At present, Tharoor resides in an Indian Navy guesthouse.