Mrs Arroyo's popularity rating is at a record low

"Let us discard dirty politics and concentrate on pushing our economy," she said in a speech to mark the country's Independence Day.

Mrs Arroyo denies accusations that she rigged last year's presidential vote.

Anti-government protests failed to draw large crowds in Manila on Sunday, where security forces were on high alert.

Security was stepped up for the holiday weekend as the government warned of a plot to unseat the president.

On Saturday, about 5,000 people held a peaceful protest calling for Mrs Arroyo to resign to avoid dividing the country.

Bitter election

Opposition senators believe Mrs Arroyo fixed last May's election and also accuse members of her family of taking pay-offs from illegal gambling syndicates. The accused deny all the allegations.

Mrs Arroyo beat popular film star Fernando Poe by 3% of the vote to win her first electoral mandate since she assumed the presidency in 2001. As vice-president, she had taken over the presidency after a popular revolt against her predecessor Joseph Estrada.

Mr Poe died of a stroke in December while Mr Estrada remains in prison on corruption charges.

The Philippines has seen two popular revolts and at least a dozen coup attempts in 20 years.