The generals say approval of the constitution at the May 10 vote will pave the way to elections in 2010 under their 'roadmap' to democracy.

In a May Day message, Senior General Than Shwe urged workers to vote for the charter, the New Light of Myanmar newspaper reported.

'I would like to urge the mass of the workers to take part in the tasks whatever role they are in for approval of the draft constitution,' the reclusive junta leader said.

But Human Rights Watch said widespread repression, a lack of media freedom, bans on political meetings and arrests of opponents of the constitution showed conditions for a free and fair vote did not exist.

The vote is being held just months after the junta last September violently suppressed mass demonstrations led by Buddhist monks, leaving 31 dead according to the United Nations.

'The Burmese generals are showing their true colours by continuing to arrest anyone opposed to their sham referendum, and denying the population the right to a public discussion of the merits of the draft constitution,' Mr Brad Adams, Asia director at Human Rights Watch, said in a statement on the release of a report on the referendum.

The draft constitution emerged from a 14-year-long military-backed National Convention of mainly handpicked delegates, which was boycotted in its later stages by the opposition National League for Democracy headed by detained Nobel laureate Aung San Suu Kyi.

In its report titled 'Vote to Nowhere: The May 2008 Constitutional Referendum in Burma', the New York-based rights group said the proposed charter entrenched the junta's role by reserving a quarter of seats in both houses of parliament and certain cabinet posts for the military.

Since amendments to the constitution require support from three-quarters of members in both houses, the military holds an effective veto.

Clauses also provide for the exclusion of many opposition politicians from running for office and one prevents Ms Aung San Suu Kyi from holding any elected office because she is the widow of a foreigner, British Tibetan scholar Michael Aris.

'On its face, both the referendum and the draft constitution are designed to constitutionally enshrine and forever entrench more of the same abusive rule that Burma has endured already for nearly half a century,' the report said.

Human Rights Watch pointed out that most Myanmar citizens have not even seen the document they are expected to vote on.

The 194-page document was released only a month before the referendum but has had limited circulation and is only available in Burmese and English, while an estimated 40 per cent of the population speak one of the 135 other languages used by the country's ethnic minorities and do not read Burmese or English, it said.

Human Rights Watch said the military had also 'stepped up its repression' since announcing the referendum in February 2008, 'detaining those expressing opposition to the draft constitution.' 'You can't hold a free and fair referendum when you deny every basic right to your people', Mr Adams said.

'The generals expect the Burmese people to just shut up, follow their orders, and approve the draft constitution without any discussion or debate.'

'That's not exactly how democracies are born.' -- AFP