Chennai, May 17: An AIADMK lawmaker today resigned his seat in the nick of time to beat an Election Commission convention and enable Jayalalithaa to enter the Tamil Nadu Assembly through a byelection.

Speaker P. Dhanapal accepted the resignation of P. Vetrivel and immediately notified the vacancy in north Chennai's R.K. Nagar constituency in the state gazette.

Since the current Assembly's term expires on May 22 next year, it was necessary for a vacancy to be notified before May 22 this year. The poll panel does not usually hold by-elections if a vacancy obtains less than a year before the House's term expires.

Jayalalithaa is expected to be elected leader of her party MLAs, who now number 150 in a House of 234, on Friday morning and sworn in as chief minister later in the day.

She was unseated as chief minister and MLA following a corruption conviction in September but became eligible for both posts after her May 11 acquittal by Karnataka High Court.

Vetrivel, who had defected from the Congress in 2001, told The Telegraph: "This is the least I can do for my leader. I'm honoured she would be contesting from this seat. She'll win by over one lakh votes."

Jayalalithaa has never before contested from a Chennai seat but R.K. Nagar has been an AIADMK bastion since 2001, with the support largely coming from its slum dwellers and fishing community.

"Since R.K. Nagar comes under the Chennai Corporation limits, addressing civic issues becomes easier," a former AIADMK minister said.

Jayalalithaa had been offered seats even by rebel MLAs from the DMK and Vijayakanth's DMDK but has chosen to stick to a seat belonging to her own party. Today's development means she may not now opt for early Assembly polls.