PARIS: Flights in and out of Paris and across France were severely disrupted on Wednesday when air traffic controllers staged a one-day strike in protest at plans to unify west European airspace under a single authority.

Controllers fear the plan could lead to job losses and cuts in some of their benefits but one of the biggest trade union confederations, the CFDT, condemned the strike as an unnecessary hassle for holidaymakers.

“Sometimes it is better to negotiate than embark on strikes that hinder travelers,” CFDT Secretary General Francois Chereque told RTL radio.

“Many people are going on holidays. They are tired. They have had a difficult year because of the [economic] crisis. They need a break and this is not the time to annoy them,” he said.

The strike, called by several controllers’ unions, forced the cancellation of about 20 percent of flights at Paris’ Charles de Gaulle airport, the nation’s biggest. The second-busiest airport, Paris Orly, was worse hit with about 50 percent of cancellations, civil aviation authorities said.

Some 22 percent of flights were cancelled at Marseille Provence airport, 14 percent at Lyon St-Exupery and 6 percent at Nice Cote d’Azur.

Government spokesman Luc Chatel told the LCI news channel that the strike was  “unacceptable” and would place many travelers going or returning from holidays in a hostage situation.

Flag carrier Air France said it would maintain 100 percent of long-haul flights, 80 percent of short and medium-haul flights out of Charles de Gaulle airport, and 50 percent of short and medium-haul flights at Orly airport.

“Some cancellations during the day Wednesday cannot be ruled out, as well as some delays,” Air France said.

The proposal of a single airspace authority for the 27-nation bloc has been in discussion since 1960. A volcanic ash cloud emanating from Iceland which forced the closure of a major part of European airspace in April highlighted the disjointed and uncoordinated response.

France is one of six European states – including Belgium, Germany, Luxembourg, the Netherlands and Switzerland – which signed a deal two years ago to create a single central European airspace bloc, as part of broader plans to gradually unify air traffic control in the whole of Europe.