Louise Williams, Jakarta – Indonesian security forces have announced a crackdown on supporters of the democracy leader Ms Megawati Sukarnoputri after her backers and the main Muslim party moved to forge an opposition alliance for the coming national elections.

Ms Megawati, ousted leader of the Indonesian Democratic Party (PDI), is banned from taking part in the election campaign, leaving the Muslim-led United Development Party (PPP) as the only real alternative to the ruling Golkar movement in the May 29 elections.

Hundreds of thousands of PPP supporters rallied across Java at the weekend, and the appearance of posters, T-shirts and banners linking Ms Megawati to the PPP fueled speculation her supporters had found a way into politics through an unofficial alliance with the PPP.

But with another PPP rally due to be held today, the Indonesian military has announced that all symbols of Ms Megawati or the alliance will be seized.

"I call on them not to display the outlawed banners in the next rally," a military spokesman said. The General Election Committee also issued a warning that people "are not to use those banners". "Every banner has to have police clearance and the "Mega-Bintang (PPP)' banner is not in the regulations," it said.

The PPP and the Soeharto Government-backed faction of the PDI are battling Golkar for 425 elected seats in the 500-member parliament. The rest of the seats are allocated to the military, whose members are not allowed to vote.

The Soeharto-backed PDI faction appears to be doing badly in the campaign and may be routed in the polls, political analysts say. A PPP official said the PPP-Megawati alliance banners had grown spontaneously in rallies last week after Ms Megawati's supporters from one central Javanese town were granted permission to vote with the PPP against Golkar. Their only alternative is to boycott the polls.