Former Dasmariñas Vice Mayor Rex Mangubat on Tuesday became the first aspirant to file his certificate of candidacy (COC) for the 29 August special election for Cavite's 4th District congressional seat.

The special election was called by the Commission on Elections (Comelec) to fill the vacancy left by the expulsion of former Rep. Francisco "Kiko" Barzaga.

Mangubat's filing came amid growing speculation over the race, with reports also linking Dasmariñas Mayor Jenny Barzaga and former congressman Gilbert Remulla as possible contenders.

Comelec has set the filing of certificates of candidacy from 15 to 17 July, with the special election scheduled for 29 August.

Mangubat, who served as city councilor, provincial board member and vice mayor, said he is grateful for the support he has received from residents.

"I am humbled by the outpouring of support and continue to listen to the people as we move forward," he said.

The congressional race has drawn national attention following Barzaga's expulsion, only the second such case in Philippine history.