Estrada accused Mrs. Arroyo of cheating and manipulating election surveys that showed she was leading over Poe, the opposition standard-bearer.
"They stole the seat from me, now they’re stealing the victory from FPJ," Estrada told reporters by phone from his detention cell, referring to Poe’s initials.
"It’s about time that people hold protests on the streets to denounce the massive cheating."
Estrada, who is facing high-level corruption charges, was ousted during the second "people power" uprising in January 2001 and replaced by then Vice President Arroyo. Shortly after his arrest in April 2001, supporters of the fallen leader staged a third "people power" revolt and later tried but failed to seize Malacañang.
Poe’s camp earlier warned of a people’s power revolt should their candidate lose due to cheating. Earlier this week, several thousands Poe supporters trooped to the streets in Makati City to protest against Mrs. Arroyo’s early lead in exit polls and unofficial and partial quick count of votes.
Estrada, the de facto opposition head, also turned down a "unity government" being proposed by the President to heal divisiveness after the highly acrimonious campaign.
Not that he is against a government of national unity, Estrada said, but the presidential race should be won fair and square.
"The government of national unity is fine, but the president should be elected through the mandate of the people and not through cheating. No way will there be unity with GMA," Estrada said, referring to Mrs. Arroyo by her initials.
Poe’s campaign staff on Wednesday said they were collating reports of fraud in the May presidential elections.
Estrada, a former actor, lamented that survey firms and the media have not been fair to the political opposition. "They manipulated the surveys. Nakuha ni GMA lahat, pati media."
Estrada said that based on their own tabulations, Poe had clearly won in Metropolitan Manila, and yet, and exit poll conducted by the independent Social Weather Stations (SWS) showed Mrs. Arroyo leading by eight percentage points over Poe.
The SWS is the same poll firm that predicted Estrada’s victory in the 1998 presidential elections.
The results of SWS public opinion polls are no longer credible, Estrada said, citing the small margin in the vote tabulation between Mrs. Arroyo and Poe. – AFP, Delon Porcalla