PARIS • In the days after terrorists killed scores of people lounging in Paris cafes on an unseasonably warm November night in 2015, Parisians defiantly returned to their neighbourhood bistros in droves to show that they would not be broken.

The hashtags #jesuisenterrace, meaning "I am outside", and #tousaubistrot, or "Everyone to the bistro", exploded on social media as people gathered to lift a glass of wine under the heat lamps as a way to demonstrate that their way of life would continue.

"It was a sign of their power and resilience," said Ms Olivia Polski, an assistant mayor for commerce in Paris.

Now, a coalition of bistro owners, unions and trade organisations is lobbying to get Unesco - the United Nations' cultural and educational agency - to grant Paris' sidewalk bistros and cafes official status as France's "intangible cultural heritage".

For many tourists and French citizens, Paris would not be Paris without its local bistros and sidewalk cafes.

Whether small or sprawling, they are inseparable from the city's iconic image - immortalised in Hollywood movies and novels.

But are they part of the world's intangible cultural heritage?

For Mr Alain Fontaine, a bistro owner and president of the association pushing the Unesco idea, the answer is an emphatic "yes".

"For centuries, they have been melting pots, places where people of different ethnicities, professions and social classes mix," said Mr Fontaine, who owns Le Mesturet, an old-fashioned bistro with a zinc bar and chandeliers made of wine bottles.

Support for the cause has come from Parisian actors, writers and residents for whom the local cafes and bistros represent a way of life. Many attended a recent news conference at Le Mesturet to explain the rationale.

Mr Fontaine's group is up against some tough competition in France.

The "bouquinistes", sellers of old books and other printed material on the banks of the Seine, are also lobbying for the Unesco designation.

So, too, are the makers of that most recognisable of French bread, the baguette, who say that it deserves the title.

NYTIMES