Monday's strike notice comes after a strike by larger groups of workers was averted last week. Only "partial and modest gains" were offered, said the Force Ouvriere (FO) union. It represents almost 12 per cent of ADP's workforce.

Unable to make any progress, the small union, operator ADP, formally threatened to strike on Friday, the day of the Olympic opening ceremony. It rejected the latest agreement with management, which it said was inadequate. Citing a "feeling of dissatisfaction" among workers, the strike notice was issued for 05:00 (04:00 GMT) on Friday until 07:00 on Saturday.

As Friday is the day of the opening ceremony, no civil flights will be allowed within a 150 kilometre (90 mile) radius of Paris between 18:30 and midnight. This will limit the potential impact of the strike. Many flights cannot be cancelled because they are not legally permitted. In these circumstances, ADP could not immediately comment on the impact of the FO strike.

The strike is over the union's demand for an increase in a bonus agreed last week from €300 to €1,000, as well as other wage increases. This has not been achieved, forcing the workers into this situation during the Olympic Games.

The FO's strike warning comes as smaller unions representing Air France pilots and cabin crew are also set to walk out this week to protest plans to leave Orly, one of the capital's three airports. The company "will operate its full flight programme" despite the strike, a spokesman told AFP.

The threat of strikes at Paris airports has been a constant this year. In May, a strike by air traffic controllers led to disruptions. The conflict was resolved. However, the threat is always there. With all the people arriving for the Olympics and those coming for holidays to the world's most visited city, the threat of strikes at airports is something that keeps the French authorities on their toes. 

At the height of the summer, Roissy-Charles-de-Gaulle and Orly airports handle around 350,000 passengers a day. This year, with the arrival of the Olympic Games, that number could increase significantly.

The air traffic controllers' strike in June was called off. This was due to the early national elections. France in general, and Paris in particular, have experienced tense moments due to strike warnings at airports, and now there is another one. Tensions remain high just days before the start of the Games.