Supporters of President Rodrigo Duterte are converging at Plaza Miranda in Quiapo, Manila on Thursday.
They are joined by members of PDP-Laban.
Some demonstrators are wearing red t-shirts and carrying tarpaulins that call for charter change and switch to federalism.
There is no definite program prepared for the event.
Organizers expect the arrival of cabinet members like Justice Secretary Vitaliano Aguirre and Energy Secretary Alfonso Cusi.
Presidential complaints desks have been set up at the venue of the mass action.