The CPM on Saturday extended its support to the ruling AIADMK in the Yercaud bypoll, scheduled to be held on December 4.
"Taking the national and state political situations and by accepting the request made by AIADMK, CPM has resolved to support the AIADMK candidate in the Yercaud bypoll," CPM state secretary G Ramakrishnan said in a statement.
The bypoll was necessitated by the death of sitting AIADMK MLA C Perumal in July.
DMK has already nominated V Maran as its candidate for the bypoll and urged all opposition parties to extend support to the party.