Hundreds of thousands of Filipinos gathered on Sunday in the capital in the largest rally so far to demand accountability over a flood-control corruption scandal that has implicated powerful members of Congress and top government officials. Various groups have protested in recent months following the discovery that thousands of flood defence projects across one of the world’s most typhoon-prone countries were substandard, incomplete or simply did not exist.

Government engineers, public works officials and construction company executives have testified under oath in hearings by the Senate and a fact-finding commission that members of Congress and officials at the Department of Public Works and Highways took kickbacks from construction companies to help them win lucrative contracts and avoid accountability. Most denied the allegations.