In a late night development, the ruling AIADMK signed a pact with the BJP, allotting it 20 Assembly seats and the Kanniyakumari Lok Sabha (bypoll) constituency for the April 6 election.

Earlier in the day, the DMK sealed a deal for six seats with the CPI, the fourth ally to sign a seat-sharing agreement.

The Kanniyakumari vacancy was caused by the death of Congress MP H. Vasanthakumar.

The seat-sharing agreement in the ruling camp was signed by O. Panneerselvam, coordinator, and Edappadi K. Palaniswami, co-coordinator of the AIADMK, C.T. Ravi, national general secretary of the BJP in-charge of Tamil Nadu, and L. Murugan, BJP Tamil Nadu president. “It has been decided that the AIADMK and the BJP will be part of an alliance to face the Assembly poll on April 6. Based on an agreement reached between the AIADMK and the BJP today [Friday], it has been decided to allot 20 seats to the BJP under the alliance led by the AIADMK,” the statement said.

The announcement comes after multiple rounds of talks between the two parties, with Home Minister Amit Shah himself holding talks with the top two leaders of the AIADMK after his visit to Puducherry on Sunday.

In another development, Chief Minister Edappadi K. Palaniswami, his deputy O. Panneerselvam and four others figured in the AIADMK’s first list of candidates for the Assembly election released on Friday.

Mr. Palaniswami will be trying his luck again from Edappadi, his home constituency. He was elected from the seat in 1989, 1991, 2011 and 2016. Mr. Panneerselvam has been nominated from Bodinayakanur, from where he was elected in 2011 and 2016. On two other occasions, he represented Periyakulam.

Ministers D. Jayakumar and C.Ve. Shanmugam have been chosen for their respective constituencies of Royapuram in Chennai and Villupuram. This will be the seventh time that Mr. Jayakumar is being fielded from Royapuram. He lost only in 1996. Two others — S.P. Shanmuganathan and S. Thenmozhi — have been fielded from their constituencies of Srivaikuntam and Nilakkottai (reserved).

A senior office-bearer said the six nominees represented a good mix of communities — Vellala Gounder, Mukkulathor, Meenavar, Vanniyar, Nadar and the Scheduled Caste. Another functionary said the remaining candidates would be announced by Tuesday.

At Anna Arivayalam, DMK president M.K. Stalin and CPI State secretary R. Mutharasan signed the agreement. “We held talks in a cordial manner to ensure the victory of the Secular Progressive Alliance, led by the DMK,” Mr. Mutharasan said. Between the number of seats and idealism, the latter was important in this election as the objective was to prevent sectarian forces from entering Tamil Nadu.

The DMK is yet to finalise seat-sharing with the CPI(M) and the MDMK, while talks with the Congress have remained inconclusive. The CPI(M) has convened its secretariat meeting for Saturday. The issue of seat-sharing will be discussed at the meeting, to be attended by general secretary Sitaram Yechury. Likewise, the MDMK’s high-level committee will meet to decide on the offer of seats made by the DMK.