The ban on nearly all vehicle traffic in the Paris Centre district, formerly the first four arrondissements of the capital just north of the Seine river, was announced last May and set to come into effect this year with a massive impact on daily travel expected, according to AFP.

The district includes the two islands on the Seine, whose landmarks include Notre-Dame cathedral and the Sainte-Chapelle, and the winding narrow streets of the Marais.

It is one of several projects by Socialist Mayor Hidalgo to green one of Europe's densest cities and tackle chronic air pollution, by reclaiming streets for pedestrians and encouraging bicycles and other travel alternatives.

But the plans targeting drivers have proved divisive, with many complaining of huge traffic jams for residents as well as the millions of people living in suburbs having no viable public transport options for getting to work in the city.

Deputy Mayor David Belliard, in charge of transportation, said that even after the clampdown in 2024 private car trips in the centre districts would be allowed for people "going to the theatre or to visit friends" or with "something to do in the zone."

It was the second retreat this month by Paris City Hall on a key transport measure, after officials pushed back to next year a ban on older and more-polluting cars that had been set for July 1.