Article 12 3-a.

Where necessary, and for as long as is necessary, in order to protect the environmental integrity of the EU ETS, operators, aircraft operators, and shipping companies in the EU ETS shall be prohibited from using allowances that are issued by a Member State in respect of which there are obligations lapsing for operators, aircraft operators, and shipping companies. The delegated acts referred to in Article 19(3) shall include the measures necessary in the cases referred to in this paragraph.