Article D43-4 of the French Code of Criminal Procedure
On pain of inadmissibility, the request by the person under investigation for the whole of the proceedings to be examined by the investigating chamber pursuant to the provisions of Article 221-3 shall be the subject of a reasoned request to the President of this Chamber, which shall be forwarded to the latter via the Examining Magistrate in accordance with the provisions of this Article. This request shall specify whether the…