Chennai, April 19 -- In a sudden and surprise development and with the Assembly elections less than an year away, Marumalarchi Dravida Munnetra Kazhagam (MDMK) Principal Secretary Durai Vaiko, also a Lok Sabha MP from Trichy, on Saturday resigned from the party post.

Mr Durai Vaiko is the son of MDMK General Secretary Vaiko, who is also a Rajya Sabha member.

MDMK is a key ally of the ruling DMK-led Front in Tamil Nadu and also part of the Opposition Congress-led INDI Bloc at the National level.

The MDMK were caught unawares of Durai Vaiko's sudden decision to step down from the post. When he joined the party he was given the post of Headquarters Secretary before he was elevated as the Principal Secretary.

Even his father and the MDMK...