The warning came as Mrs Arroyo's top allies sought to play down fresh threats to her administration while opposition groups and the influential Roman Catholic church continued a series of demonstrations in support of a star witness who exposed alleged large-scale bribery.

Ahead of Monday's rallies marking the anniversary of the 1986 'people power' revolt that ousted late dictator Ferdinand Marcos, national police spokesman Senior Superintendent Nicanor Bartolome said officers caught attending the protests will face administrative charges that may lead to dismissal.

'They are supposed to be government employees,' he said.

About 10,000 people called for Mrs Arroyo's ouster at a rally in Manila?s financial district last Friday.

They were backed by close to 100 former government officials who signed a manifesto condemning Mrs Arroyo's 'wrongful governance' and calling on her entire Cabinet to resign.

Archbishop Angel Lagdameo, president of the Catholic Bishops' Conference of the Philippines, called for a different kind of 'people power' revolt to fight endemic corruption.

He said after meeting with about 50 civic, student and business groups Tuesday that the massive anti-corruption movement that ousted Mrs Arroyo's predecessor, Joseph Estrada, in 2001, was a disappointment because it 'installed a president who later on was judged by surveys as the most corrupt president.'

Many Catholic churches and key universities have set up 'truth centers' to collect signatures and cash donations from the public to back a key corruption witness, Rodolfo Lozada Jr, and other officials exposing government corruption.

The latest scandal battering Mrs Arroyo, who has survived four power grabs and three impeachment attempts since 2001, erupted after Mr Lozada, a former government consultant, accused a former elections chief of demanding a huge kickback from brokering a government contract with Chinese telecommunications giant ZTE.

Lozada also alleged that Mrs Arroyo's husband took part in backroom negotiations for the US$330 million (S$466 million) contract. The deal has since been aborted, and both men and ZTE have denied the allegations.

Amid coup rumors, military chief Gen Hermogenes Esperon said the armed forces will not intervene in the political crisis, but he admitted the issue was being discussed among the brass.

'What do you prefer? An armed forces that intervenes every now and then or an armed forces that would simply be constitutional, very professional, focused on its job,' he said, adding he did not believe the latest political storm will spark another 'people power' revolt. -- AP