The defence based on the existence of an arbitration clause for contractual arbitration (arbitrato irrituale) does not raise an issue of jurisdiction of the judicial authority, but contests the admissibility of the claim given that the contracting parties chose contractual resolution of the dispute by waiving judicial protection; such defence is substantive in nature and introduces a preliminary question on the merits.
The existence of an arbitration clause for contractual arbitration (arbitrato irrituale) does not exclude the jurisdiction of the ordinary court to issue a decree for payment, given that the arbitral proceedings procedure does not contemplate the issuing of ex parte orders and that the arbitration defence cannot be raised ex officio, but requires the court, in case of subsequent opposition based on the existence of the clause, to declare the inadmissibility of the claim and the nullity of the contested decree.