A client who has been informed in writing of the intervention of a subcontractor or subdelegatee who is in an irregular situation with regard to the provisions on undeclared work and who has not enjoined his co-contractor to put an end to this situation is, in accordance with l’article L. 8222-5 of the Labour Code, held jointly and severally liable for payment of the sums mentioned in Article L. 8222-2 of the same code, under the conditions provided for in article L. 8222-3 of the aforementioned code.