Unions at France's main airport, Charles de Gaulle in Paris, have threatened to call a strike over alleged bias against Muslim workers.
Karim Kherfouche (left) and Herve Bataille lost their clearance
Seventy-two workers, mostly Muslims, have lost security clearance at the airport since May 2005.
Officials say the workers posed a risk because of alleged links to groups with "potentially terrorist aims".
Unions will hold a meeting on Tuesday to discuss the strike, which could be called for the end of the month.
Didier Frassin, head of the main CGT union at the airport, told AFP news agency there would also be a march outside the prefecture in Roissy, which took the decision to remove the security clearance from the workers.
The workers, who include baggage handlers, were said to have visited Pakistan and Afghanistan.
Some of them are suing the authorities, claiming they are being discriminated against because of their religion.
Daniel Saadat, a lawyer for some of the workers who are challenging the decision, said: "It is all totally vague, they have nothing to go on, it's a scandal."
Philippe Decrulle, of the CFDT union, said: "We are waiting for proof of the threat these employees represent - not just shock statements."
Jacques Lebrot, the deputy prefect in charge of the airport, said security badges were withdrawn because the staff were "linked to fundamentalist movements with potentially terrorist aims".
The "great majority" were linked to an "Islamist movement", he said.
Badges were also taken away from "just under a dozen" people suspected of links to Sri Lankan Tamil Tiger rebels as well as from one Sikh worker.
Another 40 employees at the airport were being investigated as posing a possible security risk, Mr Lebrot said.
Interior Minister Nicolas Sarkozy said the move was necessary as a "precaution".
"It's quite right that the police services conduct inquiries and only certify those people we are certain about," he said.