The CGT trade union said it had created a new union in the western city of Bordeaux which would seek to represent around 700 bikers working locally for meal delivery platforms such as Deliveroo, Foodora or UberEats.
The initiative comes as a political debate rages in France about the quality of new jobs being created by companies such as Uber, whose drivers are mostly self-employed contractors with no job security.
Online food platforms have proliferated worldwide, allowing people to order from their local restaurants via their mobile phones, with dishes delivered to their homes shortly afterwards, often by couriers in their 20s.
Loic Notais from the new union, CGT 33, said that work conditions in Bordeaux had changed with riders now often paid per delivery, instead of an hourly rate.
“The number of delivery riders has double or tripled. There's no longer enough work for everyone,” he told AFP.
While critics say new internet platforms are providing short-term jobs for poor pay, supporters see them as flexible new ways of working, often for people looking for part-time jobs for extra income.
Companies such as Uber have fought legal battles in a number of countries over whether drivers should be classified as employees, which means the company is responsible for paying minimum wages and making social benefits contributions.