The by-election for Tongatapu 2 follows the Court of Appeal upholding the unseating of former MP Semisi Sika over breaches of electoral expense limits from the 2025 general election, leaving the seat vacant under Tonga’s first-past-the-post system. Alvin Lafu Sika, his brother, leads trader consensus at 55.5% amid a field of nine independents, while Lei Paasi, Malakai Koloamatangi, and others trade near or below 50%, reflecting fragmented support across districts like Kolofōʻou and Haveluloto. Withdrawals and targeted endorsements have consolidated some backing without producing a decisive frontrunner, sustaining tight implied probabilities ahead of the October 8 poll. Voter turnout patterns and late campaign shifts could still alter the outcome before resolution.