DMK president M K Stalin announced that the third seat was being allotted to ally Marumalarchi Dravida Munnetra Kazhagam, in line with its pre-poll agreement with the Vaiko-founded party.
According to a statement from Stalin, party trade union leader M Shanmugam and senior advocate P Wilson are the nominees for the biennial election, slated on July 18.
"The other seat is being allotted to MDMK as agreed upon earlier," Stalin said.
The DMK had agreed to allot one Rajya Sabha seat to the MDMK as part of their pre-poll agreement for the Lok Sabha election.
Earlier, it was being speculated that Singh, earlier fielded from Assam, might be nominated from Tamil Nadu with the DMK's support.
Biennial elections to fill six Rajya Sabha seats from the state will be held on July 18. They are being held to fill the vacancies that will arise due to the retirement of sitting members -- four of the AIADMK and one each from the DMK and the CPI -- next month.
Both the ruling All India Amma Dravida Munnetra Kazhagam and the DMK can send three MPs each to the Upper House by virtue of their respective strength in the state assembly.
The retiring members are: T Rathinavel, Dr V Maitreyan, K R Arjunan and Dr R Lakshmanan (all AIADMK), Kanimozhi (DMK) and D Raja (CPI), whose terms end on July 24.
Incidentally, Kanimozhi was elected to the Lok Sabha from Tuticorin constituency in the state in the general election.
According to the EC schedule, the notification for the Rajya Sabha biennial polls would be issued on Monday and the last date for filing nominations is July 8.
Scrutiny of nominations will be taken up the next day and the last date for withdrawal will be July 11, it said.
Polling, if required, will be held from 9 am-4 pm on July 18 and the counting the same day at 5 pm, it said.
The AIADMK has 123 MLAs and the DMK 100 members in the 234-member Assembly with two vacancies. DMK ally Congress has seven legislators, while the IUML one. AMMK leader TTV Dinakaran is an Independent member. A candidate needs 34 votes to get elected.
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