New Delhi, Sep 17 - Minister of State for External Affairs Shashi Tharoor, who has come under fire for his stay in a luxury hotel, had been travelling economy class much before the austerity measures were announced by the government.

Sources close to Tharoor said the minister had taken almost 5 flights from Aug 9, travelling to Bangalore, Chennai and Kochi, and on all occasions booked himself in economy class.

'The austerity measures were announced mid-August during the party's working committee meeting but it came into effect later. However, Tharoor has been on these economy flights earlier. He began taking a Kingfisher flight from Mumbai to Kochi on Aug 9,' said a close aide.

The sources also pointed out that Tharoor was unlikely to respond to Congress spokesperson Jayanthi Natarajan who disapproved of the expression 'cattle class' the minister used in his latest tweet.

Tharoor ran in a spot of trouble for a message he posted on the social networking site Twitter, in which he said he would travel 'cattle class out of solidarity with all our holy cows!'

Natarajan took strong exception to the term and, while refusing to be drawn into commenting whether any kind of disciplinary action was being initiated, said Tharoor was perhaps not conscious of the sensitivities since he was new to Indian politics.