By Sarah Toms
BBC News, Manila
The Philippine government has filed sedition charges against a man who says he has audio tapes linking the president to cheating in the 2004 poll.
Samuel Ong says he has master tapes of Ms Arroyo's conversations
The government says Samuel Ong's recordings were doctored and has warned the media not to play the tapes.
The retired intelligence official is currently in hiding.
He says intelligence agents gave him the tapes, in which President Arroyo appears to be pressing an election official for a bigger victory.
The government says the recordings are part of a plot by the opposition to destabilise the government.
President Arroyo herself has made no comment on the wire-tapping controversy, despite mounting pressure to break her silence.
Her ratings have slumped to a record low, amid accusations that members of her family have taken pay-offs from illegal gambling syndicates.
They deny any wrongdoing and nothing has been proved.
Filipinos are also angry about rising prices and persistent corruption.
In the latest protest, about 1,000 people rallied outside Congress on Wednesday, calling on President Arroyo to resign.
Analysts say mass protests of the kind that toppled Joseph Estrada as president in 2001 are unlikely.
But the scandals have unnerved investors and raised concerns that President Arroyo's attention will be diverted from much-needed but unpopular economic reforms.