Denouncing "unacceptable" working conditions in buses that have no air conditioning, half a dozen of them took a stand by wearing skirts for the day.

“Our uniform is not appropriate for these high temperatures. We envy women at moments like this,” Didier Sauvetre a driver from the CFDT union told the local Presse Ocean news site.

"Our managers say shorts are not suitable for our profession. We've opted for provocation by coming in skirts, which are allowed for female drivers."

"In this heatwave, the temperatures are reaching close to 50C behind our windscreens. As we don't have air conditioning in our buses, it's unbearable in trousers," said Gabriel Magner, another union member baring his legs.