The 2G spectrum scam that cost A Raja his chair took the steam out of DMK's preparations for the 2011 Tamil Nadu polls during the year that saw AIADMK leader Jayalalithaa taking up cudgels against the party and asking Congress to dump its ally.
Revelations of reported conversation between DMK MP Kanimozhi and corporate lobbyist Niira Radia and Raja being summoned by CBI for questioning in connection with the 2G spectrum scam added to the DMK's woes. Ms Jayalalithaa and other opposition party leaders made a major issue out of them and demanded the arrest of the former telecom minister.
This was the first time in DMK's history that the party asked one of its nominees to resign under intense opposition pressure after a report by the comptroller and auditor general of India indicted Mr Raja for his role in the 2G spectrum allocation.
Mr Karunanidhi pulled out all the stops, including playing the 'Dalit card', to save his 'affectionate brother' and let him continue as telecom minister, but in vain as Mr Raja was forced to quit after opposition parties stalled proceedings in Parliament demanding his resignation.
While Mr Karunanidhi and a few DK leaders commented on the developments, others including deputy chief minister M K Stalin and union minister M K Alagiri maintained a studied silence.
All seemed well for DMK till November as it was savouring the successful conduct of the world tamil classical conference and a spectacular win in by-elections to Pennagaram assembly constituency in PMK-dominated area.
But, the Cag report on the 2G spectrum allocation came as a dampener for DMK and incidents after Mr Raja's resignation like raids at his home and that of his aides have also raised question marks over the future of the DMK-Congress alliance.
As DMK struggled to get out of the 2G mess, Ms Jayalalithaa sought to fish in troubled waters by asking Congress and Prime Minister Manmohan Singh to dump DMK and sack Mr Raja from the cabinet with a promise of the support of 18 MPs for the coalition.
However, the Congress quickly rejected the offer.
AIADMK and its poll partners left parties also made attempts to reach out to the people by organising public meetings on the 'Himalayan corruption of the century'.
However, Mr Karunanidhi continued to defend Mr Raja and said it was a myth that a single individual could have swallowed Rs 1.76 lakh crore, the presumptuous loss projected by Cag.
DMK faced further embarrassment when the Ms Radia tapes were made public in which Mr Karunanidhi's daughter Ms Kanimozhi openly speaks against her relative Dayanidhi Maran during cabinet formation in 2009.