The other leading opposition party, the Serbian Renewal Movement (SPO), was about to join President Slobodan Milosevic's administration - which it then left a few months later following disagreements with the Yugoslav president.

Otpor's activities have included displaying an effigy of Mr Milosevic which passers-by can punch after paying one dinar

Indeed, up until a few months ago the mainstream opposition parties showed few signs of being able to overcome their deep divisions.

Their ineffectiveness or, in some cases, unwillingness to engage in serious activity, provided the determined activists of Otpor with a chance to forge ahead and come to the forefront of the opposition.

Otpor's expanding support

Otpor now claims to have over 20,000 activists - most of them young people, especially students.

But its circle of supporters has been expanding well beyond its initial student strongholds.

Otpor's members now include the first president of the current Yugoslav federation, the 79-year-old novelist, Dobrica Cosic, who joined last week.

The official propaganda campaign depicts Otpor as the shock-troops of Nato and Serbia's other enemies that are allegedly bent on the country's destruction

A nationalist who did much to nurture President Slobodan Milosevic's ideology, Mr Cosic was removed from the presidency seven years ago after several disagreements with the strongman of Serbian politics.

Otpor is not a traditional political party but a movement that often engages in unconventional activities. Street theatre is an important part of these protests.

Activities have included displaying an effigy of Mr Milosevic which passers-by could punch after paying one dinar; or painting red footsteps on the pavement - what they claimed to be Mr Milosevic's bloodied steps - leaving office for the final time.

Otpor's symbol of a clenched fist has been displayed in a wide variety of places - from posters to T-shirts.

Official propaganda portrays Otpor as the shock-troops of Serbia's enemies

Although some of these activities may appear frivolous, Otpor's campaign has done much to dispel fear among those who want to show their opposition to the government.

And for long periods of time, while the rest of the opposition was in a state of slumber, Otpor demonstrated that there was a group of people who were prepared to overcome an all-pervasive apathy and demonstrate against the regime.

Demanding free elections

Whatever the methods used, Otpor has always given proof of a seriousness of purpose.

It has continued to demand free elections, the restoration of the rule of law, the annulment of repressive legislation and co-operation with the International War Crimes Tribunal for the Former Yugoslavia which has indicted, among others, President Milosevic.

Otpor has become one of the most prominent forces within the opposition - and arguably the most dynamic among them

Otpor's hardline opposition to the regime has carried with it an increasingly heavy price-tag.

In recent months hundreds of activists have been detained by the police. Others have been beaten up by plain-clothes security personnel.

The repressive measures have been accompanied with an official propaganda campaign that depicts Otpor as the shock-troops of Nato and Serbia's other enemies that are allegedly bent on the country's destruction.

So far Otpor has managed to take in its stride whatever harsh measures the authorities have chosen deploy against it.

It has become one of the most prominent forces within the opposition - and arguably the most dynamic among them.

Whatever the rest of the opposition may think about this relative upstart among their ranks, they have now little chance of achieving any of their objectives unless they work hand-in-hand with Otpor's clenched fist.