As many as 850,000 passengers could see flights disrupted due to a strike next Thursday by air traffic controllers in France, Germany, Spain and Portugal.

French controllers are also threatening to extend their action and Italian controllers could walk out the following week.

The disruption will not only have an impact on passengers flying to the countries involved in industrial action, but also those whose journey would take them across air space where controllers have walked out.

Airlines said they will not be able to calculate the full extent of the disruption they face until early next week, the Daily Telegraph reported.

Aviation ministers across Europe have been urged by senior industry figures to intervene in the dispute, over plans to streamline European air traffic control.

Iata director general and chief executive Tony Tyler and Athar Husein Khan, acting secretary general of the Association of European Airlines, told transport ministers the stoppage would cost airlines nearly £230 million if it goes ahead.