5.13.5.What happens if the requirement to file the translation or declaration is not observed? 

5.13.017If the applicant does not provide the translation of the priority document in time, the right of priority is lost and the applicant is informed accordingly. This has the effect that the intermediate document(s) which resulted in the validity of the priority claimed becoming relevant for the assessment of patentability will belong to the prior art under Article 54(2) or Article 54(3) EPC, as applicable.

5.13.018If the priority right is lost, further processing can be requested and will be granted if within two months of notification of the loss of rights the required translation or declaration is filed and the fee for further processing paid.