DMK President M K Stalin Friday urged the Election Commission to hold by-polls for 21 vacant assembly seats in Tamil Nadu simultaneously with the Lok Sabha elections, due by May.

A delegation headed by Rajya Sabha MP and DMK leader Kanimozhi submitted a letter addressed to the EC by Stalin at the office of the poll panel in New Delhi, a party release said here.

"We request the ECI to hold elections to the 21 Assembly seats along with election to 39 parliamentary seats in Tamil Nadu," Stalin said in the letter, a copy of which was released to the media here.

The DMK chief said this would save time of voters, the EC and government staff and also ease the burden on the public exchequer.

Of the 21 seats, as many as 18 had fallen vacant following the disqualification of ruling AIADMK MLAs loyal to ousted leader TTV Dhinakaran by the Assembly Speaker in September 2017, which was upheld by the Madras High Court late last year.

The court had also lifted an earlier stay on notifying the seats as vacant.

Two other seats are vacant after the death of sitting members -- then DMK president M Karunanidhi (Tiruvarur) and A K Bose (Tiruparankundram) -- while Minister Balakrishna Reddy representing Hosur constituency was disqualified after being sentenced to three-year imprisonment in a criminal case.

Stalin said, "Since the 21 assembly seats form part of the some of the 39 parliamentary constituencies, it would be easy to enforce election related guidelines including the model code of conduct..."

Such a move would also benefit political parties as there would be no need to conduct separate poll campaigns, the DMK President said.

"Also, electoral rolls are going to be the same for both the elections, logic demands that the elections must be held together," he added.