Citing reports in a section of media, DMK president M Karunanidhi said the hike had been effected without getting the approval of Tamil Nadu Energy Regulatory Commission.
"On behalf of the DMK, I insist that the power tariff hike effected for the second time should be rolled back," he said in a statement.
DMDK founder and Opposition Leader in the Assembly Vijayakant termed the increase as "unprecedented" and said the ruling AIADMK had earlier effected a hike within months after coming to power in 2011.
Vijayakant suggested administrative reforms, prevention of power theft and opting for low-cost wind energy to address the issue of financial losses for state-run Tamil Nadu Generation and Distribution Corporation Ltd.
PMK founder S Ramadoss, MDMK leader Vaiko and CPI (M) also flayed the tariff revision and sought its immediate rollback.
