A day after political parties, including DMK, demanded action against him for allegedly pursuing caste politics, PMK leader S Ramadoss on Tuesday charged DMK chief M Karunanidhi with "disguising" himself as a friend of Dalits.

In a statement, Ramadoss said Karunanidhi had formed a coalition in 2001 by aligning with all caste leaders and had termed it as an 'accomplishing coalition'.

"In order to retain power, if he (Karunanidhi) formed a coalition by joining hands with various castes, it is an accomplishing coalition. When we bring together the groups of castes to save them from revenge, it is termed as caste politics", he said.

The PMK leader said Karunanidhi was "disguising as a friend of Dalits" and he had failed to protect them in 1968 when his party was in power.

Karunanidhi on Monday said caste-politics was dangerous and Ramadoss was playing with fire. He demanded that government should act against those indulged in caste-politics.

Several political parties attacked the PMK leader for his attempt to bring together leaders of various castes on a common platform to campaign against inter-caste marriages.