(6)in Article 17a, the following paragraphs 5 and 6 are added:‘5.With effect from 1 July 2027, national authorities shall, in the case of new vehicles in the scope of Implementing Regulation (EU) 2025/2161 which do not comply with the requirements of this Regulation as amended by Commission Regulation (EU) 2026/361note, consider certificates of conformity issued in respect of those vehicles to be no longer valid for the purposes of Article 48 of Regulation (EU) 2018/858 and shall, on grounds relating to emissions, prohibit the registration, making available on the market and entry into service of such vehicles.6.With effect from 29 May 2029, national authorities shall, in the case of new vehicles and engines, consider certificates of conformity issued in respect of those vehicles to be no longer valid for the purposes of Article 48 of Regulation (EU) 2018/858 and shall, on grounds relating to emissions, prohibit the registration, making available on the market and entry into service of such vehicles, except in the case of replacement engines for in-service vehicles, and engines for vehicles produced by small-volume manufacturers as set out in Regulation (EU) 2024/1257 of the European Parliament and of the Councilnote.By way of derogation from the first subparagraph, with effect from 29 November 2027 for new vehicles of category M1 and N1 falling in the scope of Regulation (EU) 595/2009, national authorities shall consider certificates of conformity issues in respect of those vehicles to be no longer valid for the purposes of Article 48 of Regulation (EU) 2018/858 and shall, on grounds relating to emissions, prohibit the registration, making available on the market and entry into service of such vehicle.By way of derogation from the first subparagraph, with effect from 1 July 2030 for new vehicles of category M1 and N1 constructed by small-volume manufacturers as set out in Regulation (EU) 2024/1257, national authorities shall consider certificates of conformity issues in respect of those vehicles to be no longer valid for the purposes of Article 48 of Regulation (EU) 2018/858 and shall, on grounds relating to emissions, prohibit the registration, making available on the market and entry into service of such vehicle.By way of derogation from the first subparagraph, with effect from 1 July 2031 for new vehicles of category M2, M3, N2, and N3 constructed by small-volume manufacturers as set out in Regulation (EU) 2024/1257, national authorities shall consider certificates of conformity issues in respect of those vehicles to be no longer valid for the purposes of Article 48 of Regulation (EU) 2018/858 and shall, on grounds relating to emissions, prohibit the registration, making available on the market and entry into service of such vehicle.notenote