By Achmad Sukarsono

JAKARTA, May 1 (Reuters) Tens of thousands of workers today rallied across Asia on Monday in peaceful May Day demonstrations for better conditions.

Workers staged protests in a dozen cities across Indonesia, including one in Jakarta that attracted more that 10,000 people, against government plans to revise a 2003 labour law that businesses say is too worker-friendly and hinders investment.

''We have 14,000 officers on alert ... all over the city,'' Jakarta police spokesman Ketut Untung Yoga said ahead of the May Day rallies. ''We are prepared for any number that can turn out. Police are also ready everywhere else in Indonesia where there are workers.'' Most of the Jakarta protesters massed at the capital's main roundabout, the presidential palace and the national parliament, where workers burned a mock coffin.

Barbed wire and water cannon were visible at those central Jakarta locations, but by mid-afternoon no significant violence had been reported.

Workers want a 2003 labour law to stay untouched while employers say it gave workers so many benefits and so much freedom to organise and strike it dealt a blow to Indonesia's economic competitiveness and attractiveness to investors.

''We want to show the leaders that we don't want to succumb to the ways of the foreign investors. If all workers unite, we can reach our demands,'' a female speaker told a rally in front of the presidential palace.

The government and current parliament, elected in 2004, want to amend the law to give employers more flexibility, curb strikes and ease back on severance payments for sacked workers, currently among the world's most generous.

''We are not the reason for the bad investment climate but why are we being the sacrificial lamb,'' rally leader Suryadi told Reuters, arguing corruption and bureaucracy were the major obstacles to investment in Indonesia, not workers' rights.

PHILIPPINES PROTESTS Similar protests with thousands of participants hit at least 12 other cities in the world's fourth most populous country, local media reported.

Several opposition legislators met rally representatives and promised to knock down the government draft amendments if they reach the parliament.

The 2003 law was a product of the country's first democratic parliament after the 1998 fall of autocratic President Suharto, who kept unions on a tight leash.

In the Philippines, thousands marched in central Manila under the eye of 5,000 anti-riot police ready to thwart any repeat of May Day riots in 2001 when supporters of former president Joseph Estrada stormed the presidential palace.

In today's sweltering heat, a crowd of labour groups and Estrada supporters waved flags and banners calling for higher ages, lower fuel prices and the ousting of President Gloria Macapagal Arroyo.

Estrada is under house arrest while facing trial for corruption.

In Cambodia, anti-riot police broke up a peaceful but unauthorised May Day march by hundreds of workers in Phnom Penh led by opposition leader Sam Rainsy, which brought the capital to a standstill for a couple of hours. Japanese workers marched in a May Day rally in Tokyo.

Reuters SB RS1459