Maran's exit became inevitable when earlier in the day on Sunday, a key decision-making committee of DMK, which rules the southern state of Tamil

Nadu, in an unanimous resolution, urged party chief and state Chief Minister M Karunanidhi to initiate action against Maran.

The committee wanted Maran's removal from the government because of his "recent approach and activities" which the committee felt was "violative" of party discipline and "tarnished" the party's image.

The committee also decided to serve a show-cause notice to Maran, a grand nephew of Karunanidhi, and authorized the Chief Minister to consider his primary membership of the party after receiving his reply.

Armed by the committee's decision, Karunanidhi wrote a letter to Prime Minister Manmohan Singh urging him to drop Dayanidhi Maran from the cabinet.

However, soon after the DMK committee meeting, Maran, who was holidaying in a famous hill resort of his home state, spoke to the Prime Minister and faxed his resignation to him.

In a statement, he rejected the charge that he had betrayed DMK or its chief Karunanidhi.

The action against Maran came four days after a feud in the DMK's first family burst into open when supporters of M K Azhagiri, elder son of Tamil Nadu Chief Minister, attacked a vernacular newspaper owned by Dayanidhi Maran's elder brother Kalanidhi Maran, published a survey which favoured Azhagiri's younger brother M K Stalin to succeed Karunanidhi as his political heir.