Although anti-globalisation activists often gather at these sorts of meetings, Singapore police say they will make no exceptions to a ban on outdoor demonstrations and marches because terrorists could exploit them to mount an attack.

"The government has said that they do not want outdoor demonstrations during this event because of security concerns," said Chee Soon Juan, chief of the Singapore Democratic Party. "But that is a fallacy. This government does not tolerate any protests at all."

"We will go ahead to protest and we are prepared to face up to the consequences," Chee declared.

Police said they would arrest any lawbreakers, who could also face caning.

Chee, an acerbic critic of the government, said his protest was aimed at highlighting the widening income gap in Singapore as well as government restrictions on free speech.

Singapore expects 16,000 delegates -- including the world's financial elite of central bankers and finance ministers -- to attend the September meetings.

Public protests are rare in Singapore. Any public gathering of more than four people requires a police permit and a person convicted of unlawful assembly can be fined up to S$1000 (US$635).

In August last year, dozens of anti-riot police were sent to disperse four people who stood quietly outside a public building, wearing T-shirts which called for greater transparency in state institutions.

Chee and his sister, Chee Siok Chin, are embroiled in a libel suit launched by Prime Minister Lee Hsien Loong, and his father Lee Kuan Yew.

The Lees say they were defamed in the Democratic Party's January newsletter, which criticised the government for its handling of a pay-and-perks scandal at the country's biggest charity.

Chee has had several run-ins with the ruling People's Action Party. He was slapped with a defamation suit in 2001 for accusations against Lee Kuan Yew, founder of the modern city-state, and former Prime Minister Goh Chok Tong.

Chee was declared bankrupt in February for failing to make libel payments of S$500,000. He was jailed for eight days in March for questioning the independence of Singapore's judiciary.

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