The strikes have been running for 19 days, causing major transport chaos at one of the busiest times of the year to travel.
BFMTV reported that hundreds of demonstrators crowded into the station, with some setting off a series of smoke bombs inside the corridors, briefly stopping the escalators and blocking access to part of the station. Some protesters were filmed carrying flares.
Monday’s protests also affected the Gare du Nord, which is also home to the Eurostar terminal in Paris, and the Gare de l’Est.
French President Emmanuel Macron has appealed to the unions to call off the strikes over the holiday period, but has refused to give any concessions to their concerns. The contentious reforms involve rolling multiple pension plans into one, and increasing the retirement age.
The unions, meanwhile, have expressed concern that the new scheme will force people to work for longer and for less money, and have refused any truce. They say the government is not listening to what people on the street are saying, and are planning a new round of strikes in January.
French transport could be further affected into 2020 as airline crews and oil depots workers are expected to join the strike.
