Opposition parties in Georgia are holding what they hope will be the largest-ever rally against President Mikhail Saakashvili.
Tens of thousands of Georgians are protesting outside parliament in the capital, Tbilisi, urging President Mikhail Saakashvili to step down.
The crowd also called for early parliamentary elections.
They accuse Mr Saakashvili of heading a corrupt, authoritarian government and want him to be ousted democratically.
They accuse Mr Saakashvili of heading a corrupt, authoritarian government and want him to be ousted democratically.
The government strongly rejects the allegations, and has warned the opposition not to cause chaos.
The government rejects the claims. It is Georgia's worst political crisis since the 2003 Rose Revolution that swept Mr Saakashvili to power.
The rally is the biggest internal challenge the president has faced since coming to power four years ago.
Elections are not due until late 2008.
The country's previously weak and divided opposition parties formed a united front last month, and began a nationwide protest campaign against the Georgian leader.
The country's previously weak and divided opposition parties formed a united front last month, and began a nationwide protest campaign against the Georgian leader.
They are demanding early elections which they believe they could win.
The BBC's Matthew Collin in Tbilisi says they are also hoping to capitalise on discontent with the widespread poverty in Georgia.
They are also hoping to capitalise on discontent with the widespread poverty in Georgia - a country which is still struggling to recover from years of post-Soviet economic decay, instability and civil war.
The country is still struggling to recover from years of post-Soviet economic decay, instability and civil war.
Concessions demand
Concessions demand
Kakha Kukava, a Conservative Party lawmaker, denied the opposition was trying to stir up more social unrest.
Kakha Kukava, a Conservative Party lawmaker, denied the opposition was trying to stir up more social unrest.
"We are not calling people for a revolution, we are calling people for a protest," he said.
Mr Saakashvili says he has rescued Georgia's economy"We are not calling people for a revolution, we are calling people for a protest," he said.
"We are demanding fair elections and we think that it's very important for Georgia just now to make the first precedent to replace the government on the basis of elections, not on the basis of revolution."
"We are demanding fair elections and we think that it's very important for Georgia just now to make the first precedent to replace the government on the basis of elections, not on the basis of revolution."
Many of President Saakashvili's policies remain popular.
Many of President Saakashvili's policies remain popular.
The president said on Thursday that Georgia was a failed state before he came to power but had now become a model of democratic development and economic reform.
The president said on Thursday that Georgia was a failed state before he came to power but had now become a model of democratic development and economic reform.
The Georgian president has already suggested minor changes to the electoral process to ensure more opposition representation in parliament.
He has already suggested minor changes to the electoral process to ensure more opposition representation in parliament.
But the opposition parties want even more dramatic concessions.
But the opposition parties want even more dramatic concessions.
They have vowed to maintain their protests, around the clock, until they win.Are you in Tbilisi? Have you been affected by this demonstration? Please send your comments by using the form below.
They have vowed to maintain their protests, around the clock, until they win.
Are you in Tbilisi? Have you been affected by this demonstration? Please send your comments by using the form below.
