Article 336 of the French Code of civil procedure

The claimant in formal guarantee may always request, with his removal from the case, that the guarantor be substituted for him as principal party.

However, the guarantor, although removed from the case as principal party, may remain in it for the preservation of his rights; the original claimant may request that he remain in it for the preservation of his.

Original in French 🇫🇷

Article 336

Le demandeur en garantie formelle peut toujours requérir, avec sa mise hors de cause, que le garant lui soit substitué comme partie principale.

Cependant le garanti, quoique mis hors de la cause comme partie principale, peut y demeurer pour la conservation de ses droits ; le demandeur originaire peut demander qu’il y reste pour la conservation des siens.