French public sector workers will strike during the July-August Paris Olympics, the heavyweight CGT union federation said Thursday, adding it would file formal strike notices next month.

"Our warnings must finally be heard," CGT chief Sophie Binet told broadcaster Franceinfo, saying vital questions such as overtime work, lodging and childcare facilities had not been addressed.

The strike notice would cover people working in central and local government, as well as medical and social workers.

"Hundreds of thousands of workers will be battered by the Games," Binet said, including with overtime and restrictions on taking time off.

"We're asking what will be the social conditions of this work, how will all the workers who have to come to the Paris region for the Olympics be housed?" she added.

"How will their children be taken care of when it's the school holidays at the same time? What bonuses will they get? So far nothing has been sorted out on this side."

The announcement follows a call last month for a "social truce" without strikes from Paris Olympics organising committee chief Tony Estanguet.

Instead, Binet on Sunday demanded a meeting with Prime Minister Gabriel Attal to discuss the issue.

Only a few public sector workers have been told what support they will get during the Games, with Interior Minister Gerald Darmanin saying police working in the Paris region will get a bonus of up to 1,900 euros ($2,070).

Talks have started in other fields on compensating overtime and missed holidays, including for hospital and transport workers.