By Jonathan Charles BBC, Annemasse, France

France and Switzerland are ready - after months preparing for the worst, the security operation they have put in place is about to be tested.

Tens of thousands of demonstrators have descended on the French-Swiss border close to Geneva.

Over the next few days, they are hoping to make their collective voice heard.

The protesters want to cause disruption without violence

They have gathered to protest, en masse, against the summit of leaders from the Group of Eight, the world's most industrialised nations plus Russia, which is being held just down the road in the French spa town of Evian.

The protesters want to cause the maximum disruption without succumbing to violence.

They know most of the delegates will have to travel in and out of the security zone which surrounds the summit to get to their hotels.

If they can disrupt the entry and exit points, they think world leaders like George W Bush, Tony Blair and Jacques Chirac will have to take note of their concerns.

United behind slogan

Many of those that I have met are young, in their late teens or twenties - they are full of ideals about the way the world should be

The demonstrators are a disparate lot. Some represent groups which campaign on environmental issues.

Others are black balaclava-wearing anarchists who just believe that the governments attending the G8 are not representative of their citizens.

Then there are newer groups who dislike the recent use of military force by America and Britain against Iraq.

Police are angry that protesters are stretching their resources

Whatever their hues though, they are all united behind the slogan that the G8 lacks democratic legitimacy.

Almost as soon as I arrived in the French town of Annemasse, the temporary base for many of the protesters, I was handed a programme outlining their opinions.

The paper describes this mass movement as "peaceful and constructive protest against the power politics of the G8".

It goes on to say: "The leaders... are, without any democratic legitimacy, meeting to decide on the world's future."

Full of ideals

They're young - when they grow up, they'll realise what a waste of time all this campaigning is Annemasse resident

Most of the protesters here are camping at the town's airport, a site hastily requisitioned by the French authorities to house the thousands of people who have come here.

There they have set up stalls full of campaign slogans and leaflets.

Many of those that I have met are young, in their late teens or twenties. They are full of ideals about the way the world should be.

One local resident from Annemasse, watching the protesters, told me: "They're young - when they grow up, they'll realise what a waste of time all this campaigning is."

On Sunday though, these young people will take part in a mass demonstration on the road from here to Geneva - hoping that their sheer numbers will attract the G8's attention.

Police angry

The authorities worry that, as in the past, all these protests could be hijacked by the violent minority. They've vowed to detain anyone with black baraclavas or weapons.

For the authorities, this summit is not just a security headache - it's a full-blown migraine

Thousands of extra police have been brought in, not just from France and Switzerland but also from neighbouring Germany. Helicopters fly overhead, constantly, to monitor developments.

The police hope that their security zones around the summit will not be penetrated.

Some of the police are angry, they told me that the more effort they have to expend on containing the protesters, the less they'll have to spare to combat their real enemy - terrorist groups who might consider the G8 summit an attractive target.