By Valerie Jones BBC News Corespondent in Paris

Charles de Gaulle airport was strangely quiet - check-in desks closed, few passengers around and occasionally - very occasionally - the distant rumble of a plane taking off.

The Civil Aviation Authority in France says only around 12% of flights will be operating today.

As the morning went on, the number of cancellations on the departure boards increased.

The air traffic controllers are taking part in a day of protest by public service unions. Those involved are workers from the railways, public transport, the post office, the phone company, France Telecom - the list goes on.

Mass protest

They have been arriving for a march and rally in the centre of Paris - a protest with an air of carnival about it.

Tens of thousands of workers are taking part. As they assembled, the union flags were flying, and pop music played from loudspeaker vans as mobile food stalls did a roaring trade in hotdogs and sandwiches.

Delays and frustration for air passengers

But the protest is about fears of an uncertain future as France faces tougher economic times in a more competitive Europe.

The workers are worried about possible privatisation of public services and job cuts.

France is facing a wave of industrial unrest at the moment and the attention is focused on how the comparatively new centre-right government will handle it.

Turning the screw

On Monday, they got tough. Attempts by striking lorry drivers to block major roads in France dissipated when the police moved in quickly dispersing the blockades and threatening to take away the strikers' driving licences.

In the past the lorry drivers have been able to bring France to a virtual standstill but this French government was determined it would not let this happen.

There is more tolerance of industrial action in France than in Britain. Demonstrations, marches and strikes are almost a matter of routine.

There is a widespread view that people have the right to protest.

But the French Government is making it clear it will not let the French economy be weakened as a result.