can anyone advise me if you can lay a parquet floor in a conservatory ?

no the difference from cold nights to very warm days will be to great and the floor will rise and buckle ,laminate or tiles are the best option for consevatories

there is no problem fitting this in a conservatory,use a bitumen type adhesive, thai will give you some damp proofing protection,regards Terry.

yes, as long the conservatory sub floor is dry and was laid proprerly with an appropriate damp proof membrane. The concrete floor can then be overlayed with plywood and then the parquet flooring can be glued to the ply.