An arbitration clause contained in a contract between a professional and a consumer is presumed to be unfair pursuant to Article 33, paragraph 2, letter t), Legislative Decree 6 September 2005, No. 206, unless the professional proves the existence of specific individual negotiation characterised by seriousness, effectiveness and individuality. In the absence of such proof, the clause is null and void pursuant to Article 36, paragraph 1, of the same decree and cannot ground an objection of lack of jurisdiction in favour of arbitration.