Workers at the Marseille Saint-Charles station walked out on July 31 to press their company for salaries, according to broadcaster France 3.
"Today, we are not saying give us a raise, but pay our salaries," said Kamel Djeffel, spokesperson for the trade union Solidaires CAT, the media outlet reported on Monday.
Workers of the cleaning company, Laser, are fighting for delayed salary payments and poor working conditions.
Garbage was seen piling up inside the station, as trash cans were overfilled.