Protesters march at the financial district of Makati to press for the resignation of beleaguered Philippine President Gloria Macapagal Arroyo
The Philippine capital has witnessed the largest demonstration demanding the resignation of President Gloria Macapagal Arroyo, over allegations that she cheated in the 2004 elections.

Tens of thousands of Filipinos from political parties and private organizations, from the left and the right of the political spectrum, streamed through Manila's financial district to demand President Gloria Macapagal Arroyo step down.

The police said at least 40,000 people took part in the march, shouting slogans and carrying large signs while entertainers performed songs and dances on a makeshift stage.

Demonstrator Jenny Manuel of the Alliance of Health Workers says Mrs. Arroyo, who is known by her initials GMA, must resign because of claims that she cheated in last year's presidential election.

"We are calling for the resignation of Gloria Macapagal Arroyo because ... she manipulated the votes of the people," he said.

Professor Pedro Abraham of the University of the Philippines, whose group, Struggle of the Masses, played tribal music during the march, says he voted for Mrs. Arroyo, but then became disillusioned.

"Ultimately it is the people's voice that has to be heard at a time like this, when we have a president who is no longer credible, who is no longer the epitome of good sense and decency that every president, every leader of our nation, should be," said Professor Abraham.

The security forces were placed on high alert before the protest. But despite the large turnout, the march fell far short of the hundreds of thousands who took to the streets in 1986 and 2001, to overthrow two previous presidents, Ferdinand Marcos and Joseph Estrada.

And the political situation seems to have calmed since last Friday, when many Arroyo supporters began abandoning her and it looked like she might be forced to resign.

Speaker of the House Jose de Venecia says Mrs. Arroyo is seriously considering a proposal by 17 political parties, to amend the constitution to pave the way for a parliamentary form of government to replace the presidential system.

The proposal is an alternative to Mrs. Arroyo's resignation, and Mr. de Venecia says politicians want to move quickly in order to end the crisis.

"Our timetable is that the president will address the joint session of Congress, and immediately after July 25, a resolution will be filed in the House of Representatives," he said.

Nevertheless, Mrs. Arroyo's opponents vow to continue the protests.