New Delhi, Sep 9 : After the Congress mooted the idea that the opposition jointly contest the Rajya Sabha Deputy Chairman's post, DMK leader Tiruchi Siva's name has been almost finalised as the opposition candidate, sources said on Wednesday. The sources said that the Congress leadership had spoken to DMK chief MK Stalin, and that he had consented to the candidature of Siva, a senior party leader and fourth-time Rajya Sabha member. He has also been a Lok Sabha member in the past. When contacted, Siva neither denied nor confirm his candidature, saying "I am in my party's meeting and will come to Delhi tomorrow". The Congress sources said that party leader Ghulam Nabi Azad has also spoken to like-minded parties, including the Samajwadi Party. The sources said that the Congress wants the election to be 'opposition versus government' and not 'Congress vs BJP' contest so as to unite the opposition and corner the government in the Upper House, where it now has the upper hand. However, last minute deliberations are on with other opposition parties so that a tough contest is ensured. In the last election to the post, the Congress had fielded BK Hariprasad, who lost to NDA candidate Harivansh Narayan Singh. The Congress strategists think that a candidate from the south may force the Telangana Rashtra Samithi, YSR Congress and AIADMK to rethink their support to the BJP and may skip the poll. It would then be easy for the Opposition candidate to defeat the NDA nominee. In the numbers game in the upper house, the NDA candidate can sail through with the support of many like-minded parties like AIADMK, Janata Dal-United, and Shiromani Akali Dal. "If all the non-NDA parties support the opposition candidate, the BJP may find the going tough," said a Congress MP. The election to the Deputy Chairperson's post will be held on September 14, the day Parliament's monsoon session convenes. The election will be held at 3 pm. The nominations will be accepted till noon on September 11. The post fell vacant after Janata Dal-United MP Harivansh Narayan Singh's term in the Upper House expired. He has since been re-elected to the Rajya Sabha from Bihar. /IANS