The constitutional changes would boost Yugoslav President Slobodan Milosevic's hold on power and considerably reduce the influence of Montenegro within Yugoslavia.

Vujanovic: Brutal attempt

Montenegrin Prime Minister Filip Vujanovic in a speech to the session told deputies that the changes, voted for in Belgrade, were a brutal attempt to annul Montenegro as a state.

Deputies of Montenegro's opposition Socialist People's Party, which supports President Milosevic, accused the prime minister of trying to break-up Yugoslavia with moves already taken to bolster Montengro's independence.

A proposal by the pro-independence Social Democratic Party, allies of reformist Montenegrin President Milo Djukanovic's Democratic Socialists, to immediately call a referendum on independence from Belgrade was rejected.

Compromise

The government stance is a compromise, with more radical ministers believing that Montenegro should now press ahead with a referendum on full independence.

President Milo Djukanovic fears such a move could provoke a military intervention by Belgrade.

But this week's steps by Belgrade to further centralise Yugoslavia are clearly pushing Montenegro closer to independence.

Mr Milosevic appears to have taken a calculated gamble by forcing his arch enemy, President Djukanovic, to come down off the fence over staying in the federation.

Montenegro is already independent in all but name.

The only remaining federal institution in Montenegro is the Yugoslav army, controlled by Belgrade.

In the last year, Mr Djukanovic has defied Belgrade by maintaining cordial relations with the West, and introduced the German mark as a parallel currency.

But despite continuous pressure from some of his allies in the Montenegrin Government, Mr Djukanovic has until now been reluctant to make the final move and call a referendum on independence, fearing a possible armed conflict with Mr Milosevic's supporters.

New constitution

Under the constitutional changes, agreed by the Yugoslav parliaments, the president may stand for re-election through the ballot box rather than an electoral college of deputies.

The Yugoslav president is currently elected by parliament and cannot run twice.

Parliament also passed changes in voting for its upper house. Those changes are certain to downgrade Montenegro's position by making it almost impossible for Montenegrin deputies to get elected.

Mr Milosevic, indicted by a UN court as a war criminal, has been Yugoslav president since 1997 and Serbian president since 1989.

Opposition deputies in Belgrade also condemned the changes.

"This is what we call the legalisation of tyranny," said Tomislav Jeremic of the opposition Serbian Renewal Movement.