How does a by-election work in Tamil Nadu, and why do only 2 of 7 seats vote?

How a by-election works

1. A seat falls vacant. An MLA resigns in writing to the Speaker and the Speaker accepts it (Article 190(3)(b)), dies, is disqualified, loses an election petition, or gives up one of two seats won.
2. The Election Commission sets a schedule. The Assembly Secretariat tells the Commission of the vacancy. The Commission notifies the by-election, then come nominations, scrutiny, withdrawal, polling and counting.
3. The six-month rule. Under Section 151A of the Representation of the People Act, 1951, a vacancy is to be filled within six months, unless the rest of the term is under a year or the Commission, after consulting the Centre, certifies that it is difficult.
4. Only that seat votes; the winner serves the rest of the term. The winner sits until the Assembly's term ends on 10 May 2031, unless it is dissolved sooner.

The seven seats that fell vacant in 2026

Since 29 June 2026, seven of the 234 seats have been empty, so the House has 227 sitting members.Seven seats fell vacant between 10 May 2026 and 29 June 2026; the by-elections counted on 9 October 2026 filled two of them.

“Six months end” is the date by Section 151A, counted from the day the seat fell vacant; the Commission can be excused only on the grounds above.

Why only two of the seven vote

These points are as reported up to 26 September 2026. On 1 October 2026 the Madras High Court reserved its orders in the case; the bar on the five by-elections stays while it decides. The court's position is tracked on the by-election page.

The Madras High Court has barred the Election Commission from calling by-elections in the other five seats while it hears a public-interest case. Madurantakam and Dharapuram had no election petition pending against their April results, so the Commission scheduled them.

• On 10 July 2026 the High Court's First Bench — Chief Justice S. A. Dharmadhikari and Justice G. Arul Murugan — restrained the Election Commission from issuing a by-election notification for Tiruchirappalli East, Karur, Viralimalai, Perundurai and Ambasamudram. The order came on a public-interest petition by advocate K. Venkatachalapathy, who argued that election petitions against the April winners were still pending, so a by-election could leave two people with a claim to one seat.
• The court has extended the order three times, on 31 July, 24 August and 8 September. On 24 August the Election Commission told the court it did not propose to hold by-elections in the five seats until the election petitions are decided. Chief Minister Vijay, and two of the former MLAs, have asked the court to lift the bar.
• On 24 September the High Court refused a separate plea to stop the Madurantakam and Dharapuram by-elections.

The two by-elections: Madurantakam and Dharapuram

The schedule comes from the Election Commission, as reported on 9 September 2026. Seats the court has held back: Perundurai, Karur, Tiruchirappalli East, Viralimalai, Ambasamudram.

More: the by-election hub · results · how counting works · what happens when an MLA resigns.