Thousands of people including activists and clergy gathered in the Philippine capital's main park yesterday to denounce the "pork barrel" system of government funding which they blame for spreading corruption.
Organisers said almost 20,000 people joined the rally, but observers said the crowd was much smaller, with police putting it at about 5,000 at its peak.
The crowd, which included nuns, priests and lawyers, was significantly smaller than a similar rally last year which observers said drew at least 250,000.
Such allocations are supposed to pay for the pet projects of legislators but large amounts were allegedly siphoned off. Three powerful senators have already been arrested over the controversy.
Influential Manila archbishop Cardinal Luis Tagle praised those taking part in the "march against pork" in a statement posted on a church social media site.
Many of the protesters at the rally used the issue to attack President Benigno Aquino, whom they accused of abetting the pork barrel system and of seeking a second term despite being limited by law to only one term.
"No to pork barrel. No to term extension," the placards read as protesters carried an effigy of Aquino as a pig.
Aquino, who was elected in 2010 on an anti-corruption platform, has seen his approval ratings drop amid accusations his allies are among the beneficiaries of the pork barrel system.
The president did not directly address his critics. But speaking at an event, he called on the public "to remain vigilant against those who seek to sow doubt and lies" and spread "baseless accusations".