Gay crew members working for Air France are asking to have the right to refuse to go to a country where they could "be killed for who they are".
Air France, part of the Franco-Dutch group Air France-KLM, is about to resume flights to the capital city of Iran, Tehran.
It will be the first time they’ve flown this route after an eight year hiatus, but many crew members don’t want to be part of it.
Last week Air France said it would allow female cabin crew and pilots to opt out of flying routes to Tehran after some staff said they did not want to be forced to cover their hair when in Iran.
The positive outcome for female staff prompted a Change.org petition calling for the rights of gay staff working for the airline to be protected.
The petition now has more than 20,000 supporters.
Written by a representative of the group, it says that it is “inconceivable to force someone to go to a country where his kind are condemned for who they are. The penalty is up to 74 lashes for a minor and the death penalty for an adult".
A spokesperson for the union said the option to refuse the flight had been fought for all staff, no matter what their gender or sexual orientation.
The airline issued a statement in response to controversy stating that, “Tolerance and respect for the cultures and customs in the countries served by the airline are part of the fundamental values of Air France and its staff".