The french central administration has about 65k cars. Total public sector number of cars is about 200-400k according to:

https://www.lefigaro.fr/societes/2017/12/12/20005-20171212AR...

From what I can see I'd say public sector impact on EV sale is insignificant (36k just in december).

Also in France about half of sales are to fleet buyers, and those were up to now quite conservative and buying very little electric vehicules. I assume this will start to change soon.