After days of dilly-dallying, the Congress on Tuesday announced its support to DMK candidate Kanimozhi in the Rajya Sabha polls from Tamil Nadu.

The decision signals a possible revival of ties between Congress and its erstwhile ally, which had walked out of the United Progressive Alliance and the coalition government three months ago over the Sri Lankan Tamils issue.

A statement from TNCC president B,S. Gnanadesikan said AICC general secretary Mukul Wasnik, who is in charge of the party’s affairs in Tamil Nadu, conveyed the decision to him over phone. The Congress has five members in the State Assembly.

The decision will be crucial in returning Ms. Kanimozhi to the Upper House, as it boosts the number of legislators supporting her to 32. In a House of 234 MLAs, the DMK has 23 members and has already roped in the Manithaneya Makkal Katchi (MMK) and the Puthiya Tamizhagam (PT), two small parties that have two members each.

The numbers have greatly increased the victory prospects of Ms. Kanimozhi, as the rival for the seat, the Desiya Murpokku Dravida Kazhagam (DMDK), candidate A.R. Elangovan, cannot raise his support beyond 29, even if all seven dissident MLAs in his party, cast their votes in his favour, going by the stand of the parties as on date.

Polling will take place on Thursday. The Rajya Sabha contest is for six seats and there are seven candidates. Four candidates of the ruling AIADMK and CPI’s national secretary D. Raja are assured of victory, as the combined voting base of the AIADMK, its allies and the Left parties is 170 – a number that can be divided equally among the five nominees to propel them to victory.