The alliance between the DMK and the PMK, constituents of Congress-led UPA at the Centre, is on the brink of collapse as both the parties have taken extreme stands on continuing their relationship.

While DMK leader and Tamil Nadu Chief Minister M Karunanidhi had said that the party's high-level committee meeting would be convened here this week to review the ties between the two parties, PMK founder S Ramadoss charged Karunanidhi with branding his party as a "violent".

Though both parties have been at loggerheads for quite some time, the last straw for the DMK came from an audio CD, reportedly containing a speech of PMK veteran J Guru, a close confidant of Ramadoss, threatening Union Minister A Raja and DMK legislator S Sivasankar, both hailing from Perambalur district, a Vanniyar (most backward caste) heartland and the vote bank of the PMK.

Karunanidhi said that he could not tolerate such "violent" statements. "I cannot take insults like this," he said recently.

Ramadoss said, “It was the CD containing Guru's speech made at the height of tension between DMK and the PMK in January 2008, when the police, at the instigation of Raja, foisted cases against PMK volunteers and arrested them on Pongal day.”

The cases pertained to a charge of intimidation in collecting funds for a party conference from a road contractor. Ramadoss had said the contractor did not make any complaint and Raja “made a highway department engineer and a relative of Sivasankar lodge the complaint.”

Ramadoss, who had been alleging that his telephone was tapped by police, said Guru's speech was taped by police and handed over to the chief minister.