Depollution system faulty the engine is dead car want go

Is there any fault indication on the dash where the radio display is.
Anti pollution is basically citroens way of saying emissions system so it could be as simple as a loose emissions pipe but from what you say and the car does not run it could be your catalytic converter (part of the exhaust system) has failed causing the engine management system to cut in and protect the engine.
If there is no fault apart from anti pollution showing in the radio display find someone with a diagnostic machine to give you a better idea of the fault. Hope this helps a bit.