The 'unparliamentary language' led incensed state ministers to castigate him.

'The outburst was not misplaced,' the aide said.

'He was infuriated with the lax response from some state governments. He is really burning the midnight oil to prevent the H1N1 virus from spreading more.'

A total of 54 people have died of swine flu all over the country and over 2,600 are infected.

In the Congress party, Azad is known for his soft-spoken negotiating abilities and has successfully brokered many political deals for the party in holding together the United Progressive Alliance (UPA).

Recently after the Lok Sabha elections, Azad succeeded in wooing back the DMK after the third largest constituent in the UPA coalition had threatened to move out following a row over ministerial berths.