Police rerouted early-evening rush-hour traffic as the protesters converged on a main intersection where its leaders delivered anti-government speeches.
A number of left-wing legislators joined the march, which was notable for the absence of senior key opposition leaders who would be expected to contest the May 2010 presidential elections.
The constitution limits a president to just one six-year term.
Arroyo allies are holding public hearings in Congress on amending the constitution to rewrite provisions that businessmen say exclude much-needed foreign capital from certain key industries.
However opponents allege this is a smokescreen to allow Arroyo to remain in office beyond 2010, possibly as prime minister, by changing the current presidential style of government and replacing it with a parliamentary system.
Deposed president Joseph Estrada, pardoned and freed by Arroyo last year a month after he was sentenced to life in prison for corruption, said he backed the protesters’ sentiment.
“This is only the start,” he told ABS-CBN television in an interview from his home.
Estrada said he was concerned the street protests might turn violent over the coming weeks “because the people want a peaceful change in government.
“We are not against charter change, but it should be after the 2010 election,” he added.
Crowd control units monitored the protest from a distance.
Police units in Manila and surrounding provinces were put on high alert from early Friday, manning checkpoints on key roads leading to the capital.—AFP